How to do percent equations easily

QUESTION POSTED AT 14/12/2019 - 05:45 PM

Related questions

Rachel can buy licorice sticks for $0.75 and cherry candies for $0.50 and has a budget of $25. If her expenses are represented by the equation 0.75x + 0.5y = 25, where x is the number of licorice sticks and y is the number of cherry candies, how many cherry candies can she buy if she wishes to spend the entire $25 on cherry candies?

Answer:

She can buy 50 cherry candies if she wishes to spent the entire $25 on cherry candies

Step-by-step explanation:

Cost of each licorice sticks = $0.75

Cost of each cherry candy = $0.50

Total budget = $25

Equation to represent her expenses is 0.75x + 0.5y = 25

where x is the number of licorice sticks and y is the number of cherry candies

Let the number of cherry candies she can buy be c.

So,

Cost of each cherry candy * Number of cherry candies = Total budget

=> 0.50 x c = 25

We get

0.50c = 25

We need to eliminate 0.50 from the left so we divide both sides by 0.50

\frac{0.50c}{0.50}=\frac{25}{0.50}

Cancelling out 0.50 from the top and bottom of the left side we get,

c = 50

So, she can buy 50 cherry candies if she wishes to spent the entire $25 on cherry candies.

ANSWERED AT 18/01/2020 - 01:14 PM


QUESTION POSTED AT 18/01/2020 - 01:14 PM

To solve the equation - 4 = 20, you would first add 4 to each side and then divide each side by 8. True False

False, just divide 20 by -4 to get correct answere.

ANSWERED AT 18/01/2020 - 01:08 PM


QUESTION POSTED AT 18/01/2020 - 01:08 PM

The point slope form of the equation of the line that passes through (-5,-1) and (10,-7) is y+7= -2/5(x-10) what is the standard form of this equation of the line

Standard form for y+7=-2/5(x-10) is y=-7-2/5(x-10)

ANSWERED AT 18/01/2020 - 01:07 PM


QUESTION POSTED AT 18/01/2020 - 01:07 PM

Andrew estimated the weight of his dog to be 60 lb. The dog’s actual weight was 68 lb. What was the percent error in Andrew’s estimate? Round your answer to the nearest tenth of a percent.

Correct - wrong    percentage
-------------------- = ---------------
       wrong                100
68 - 60      x
--------- = ----
   60       100
 8       x
---- = ----
60    100
800    60x
----- = ----
 60     60
13.3% = x

ANSWERED AT 18/01/2020 - 01:04 PM


QUESTION POSTED AT 18/01/2020 - 01:04 PM

Which of the following equations is written in standard form? A. 2.5x+3y=12 B. -10x-3y=1 C. 2x+3y=12 D. 5x+5y=10

C. 2x+3y=12 is written in standard form

ANSWERED AT 18/01/2020 - 01:02 PM


QUESTION POSTED AT 18/01/2020 - 01:02 PM

Which of the following equations is in slope-intercept form? A. 2y = 3x – 1 B. x = 3y – 1 C. y = –3x D. 9x = 2

C is in slope intercept form

ANSWERED AT 18/01/2020 - 12:59 PM


QUESTION POSTED AT 18/01/2020 - 12:59 PM

What is the slope of the line that is perpendicular to the line whose equation is 2x + y = 4. -2 -1/2 1/2 2

2x + y = 4
        y = -2x + 4

Perpendicular Slope: ¹/₂

ANSWERED AT 18/01/2020 - 12:59 PM


QUESTION POSTED AT 18/01/2020 - 12:59 PM

Which statements about the system are true? Check all that apply. y = x – 4 3y – x = –7 The system has one solution. The system consists of parallel lines. Both lines have the same slope. Both lines have the same y–intercept. The equations represent the same line. The lines intersect.

Answer and explanation:

Given : Equations y=x-4 and 3y-x=-7

To find : Which statements about the system are true? Check all that apply.

Solution :

First we solve the system of equations,

y=x-4  .....(1)

3y-x=-7  ......(2)

Substitute y from (1) in (2),

3(x-4)-x=-7

3x-12-x=-7

2x=5

x=\frac{5}{2}

Substitute the value of x in (1),

y=\frac{5}{2}-4

y=\frac{5-8}{2}

y=\frac{-3}{2}

1) The system has one solution i.e. (\frac{5}{2},-\frac{3}{2})

2) The system has solution which means it is not parallel lines.

Writing equation in slope from, y=mx+c

y=x-4 where m=1 and c=-4

3y-x=-7 where m=\frac{1}{3} and c=-4

3) Both lines have different slopes.

4) Both lines have the same y-intercept.

5) The equations represent the different lines.

6) The lines intersect at (\frac{5}{2},-\frac{3}{2})

ANSWERED AT 18/01/2020 - 12:54 PM


QUESTION POSTED AT 18/01/2020 - 12:54 PM

What is the solution of the equation 3y-5y+10=36 ( A) -13 (b) 4.5 (C) 13 (D) 2

3y-5y+10=36

combine like terms

-2y+10=36

subtract 10 from both sides

-2y = 26

divide both sides by -2

y = - 13

so the answer is a

ANSWERED AT 18/01/2020 - 12:52 PM


QUESTION POSTED AT 18/01/2020 - 12:52 PM

Arrange the equations in the correct sequence to find the inverse of f(x)=y=3x/8+x

To find the inverse of the the function, it must be arranged in such a way that the independent variable be on the left side and the dependent variable on the right. So,
f(x) = y = 3x/ (8 + x)
y (8 + x) = 3x
8y + xy = 3x
8y = 3x - xy
8y = x (3 - y)
8y / (3-y) = x
x = 8y / (3 -y)

Therefore,
f-(x) = f(y) = x = 8y/ (3 - y)

ANSWERED AT 18/01/2020 - 12:50 PM


QUESTION POSTED AT 18/01/2020 - 12:50 PM

Enrollment in a photography class increased from 25 to 35 students. What was the percent of increase in enrollment?

Answer

40%

Explanation

A parentage value is a value that has been compared to 100.

Percentage = (change in the value)/(the original value) × 100%

                   = (35-25)/25 × 100%

                    = 10/25 × 100%

                   = 40%

ANSWERED AT 18/01/2020 - 12:49 PM


QUESTION POSTED AT 18/01/2020 - 12:49 PM

What is 35 percent of 70

35 Percent of 70 is 24.5
We assume, that the number 70 is 100% - because it's the output value of the task. We assume, that x is the value we are looking for. If 70 is 100%, so we can write it down as 70=100%. We know, that x is 35% of the output value, so we can write it down as x=35%. Now we have two simple equations: 1.)70=100% 2.)x=35%where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that: 70/x=100%/35% Now we just have to solve the simple equation, and we will get the solution we are looking for.

ANSWERED AT 18/01/2020 - 12:47 PM


QUESTION POSTED AT 18/01/2020 - 12:47 PM

Solve the equation for the variable b. a/b = c

Just multiply both sides by b

a=cb

then divide both sides by c
 a/c = b

so b = a/c

ANSWERED AT 18/01/2020 - 12:47 PM


QUESTION POSTED AT 18/01/2020 - 12:47 PM

Convert 1.05 to a percent

Answer:

105%.

Step-by-step explanation:

We are asked to convert 1.05 to a percent.

To convert a decimal to percent, we simply multiply the decimal number by 100 and add a percentage sign.

Let us multiply 1.05 by 100.

\text{1.05 to percentage}=1.05\times 100\%

\text{1.05 to percentage}=105\%

Therefore, 1.05 as a percent would be 105%.

ANSWERED AT 18/01/2020 - 12:44 PM


QUESTION POSTED AT 18/01/2020 - 12:44 PM

Write the quadratic equation in general form and then choose the value of "b." (2x - 1)(x + 6) = 0

a=2,b=11,and c=-6 your answer

ANSWERED AT 18/01/2020 - 12:43 PM


QUESTION POSTED AT 18/01/2020 - 12:43 PM

Alexei wants to hang a mirror in his boat, and put a frame around it. The mirror and frame must have an area of 19.25 square feet. The mirror is 3 feet wide and 5 feet long. Which quadratic equation can be used to determine the thickness of the frame, x?

The first part is already in squared terms. "19.25 sq ft" Taking the measurements for the mirror 3ft and 5ft, you'd get: "15 sq ft." Subtract that answer from the previous number to get "4.25 sq ft.

Hope this helps out a little lol :)

ANSWERED AT 18/01/2020 - 12:38 PM


QUESTION POSTED AT 18/01/2020 - 12:38 PM

Peggy had four times as many quarters as nickels. She had $2.10 in all. How many nickels and how many quarters did she have? Which of the following equations could be used to solve the problem?

Value of the coin times number of coins summed up equal total value
so since we have "$2.10 in all"...
0.05n + 0.25q = 2.10

and we are told that there are "four times as many quarters as nickels"
this translates to
q = 4n

0.05n + 0.25q = 2.10
and
q = 4n
are your two equations that could be used to solve this problem


if you would like to know how many nickels and how many quarters there are, plug in q = 4n into the first equation and get
0.05n + 0.25(4n) = 2.10

multiply
0.05n + 1n = 2.10

add like terms
1.05n = 2.10

divide both sides by 1.05
n = 2.10/1.05 = 2

then plug that back into
q = 4n
so
q = 4(2) = 8

therefore you have 
2 nickels
and
8 quarters

ANSWERED AT 18/01/2020 - 12:38 PM


QUESTION POSTED AT 18/01/2020 - 12:38 PM

Find the roots of the quadratic equation x^2-8x=9 by completing the square. Show your work.

 x^{2} -8x=9 \\  x^{2} -8x+(-4)^{2} = 9 + (-4)^{2}  \\  x^{2} -8x+16 = 9 + 16 \\  (x-4)^{2} =25 \\ x-4= \sqrt{25}  \\ x-4= \pm 5 \\ x= \pm 5+4
x = 5 + 4 or -5 + 4
x = 9 or -1
 

ANSWERED AT 18/01/2020 - 12:38 PM


QUESTION POSTED AT 18/01/2020 - 12:38 PM

A line contains the points (3, –2) and (–6, –8). Write the equation of the line using point-slope form.

Y^2 - Y^1/ X^2 - X^1 os the formula that you would use to find the line that passes through those points.

ANSWERED AT 18/01/2020 - 12:37 PM


QUESTION POSTED AT 18/01/2020 - 12:37 PM

Alex has 84 quarters and nickels worth a total of $17.80. Which equation can be used to find q, the number of quarters Alex has? A. 0.25q + 0.05(q – 84) = 17.80 B. 0.05q + 0.25(84 – q) = 17.80 C. 0.25(q – 84) + 0.05q = 17.80 D. 0.05(84 – q) + 0.25q = 17.80

The value of the coin times the number of coins, summed up, equals the total value

the value of a quarter is $0.25
and quarters can be represented as a q

the value of nickels are $0.05
and can be represented with an n

there are 84 quarters and nickels in total
so
q + n = 84

which have a total value of $17.80
so
0.25q + 0.05n = 17.80

the q + n = 84 can be rearranged by subtracting q from both sides
n = 84 - q

then we can plug that into the 0.25q + 0.05n = 17.80 equation
and get
0.25q + 0.05(84 - q) = 17.80
or
0.05(84 - q) + 0.25 = 17.80

therefore your answer is D.

ANSWERED AT 18/01/2020 - 12:37 PM


QUESTION POSTED AT 18/01/2020 - 12:37 PM

The coordinates below represent two linear equations. How many solutions does this system of equations have? Line 1 x y –3 5 0 4 Line 2 x y 0 4 6 2 A. 0 B. exactly 1 C. exactly 2 D. infinitely many

Find the equations of the lines in slope-intercept form which is y=mx+b where m=slope b=y intercept
the choices:
0 solutions: means the lines don't intercect at all, meaning same slope but different y intercept or they ar paralell 
1 solution: lines intercect in 1 point 
2 solutions: curvy line with a straight line thorugh middle
infinetly solutions: same line
 



to find slope you do 
slope=(y1-y2)/(x1-x2)
first line is
(2,-7)
(0,6)
(x,y)
x1=2
y1=-7
x2=0
y2=6
subsitute
(-7-6)/(2-0)=-13/2
slope=-13/2
subsitute
y=-13/2x+b
subsitute one of the points
(0,6)
x=0
y=6
6=-13/2(0)+b
6=0+b
6=b
y=-13/2+6

now solve for the other equation


(3,0)
(0,-3)
x1=3
y1=0
x2=0
y2=-3
subsitute
(0-(-3))/(3-0)=(0+3)/(3)=3/3=1
y=1x+b
subsitute
(3,0)
x=3
y=0
0=1(3)+b
0=3+b
subtract 3
-3=b
y=x-3

we have the lines
y=-13/2x-6 and
y=x-3
solve for a common solution
y=x-3 and y=-13/2x-6 therefor
x-3=-13/2x-6
add 6 to both sides
x+3=-13/2x
multiply both sides by -2
-2x-6=13x
add 2x to both sides
-6=15x
divide both sides by 15
-2/5=x
subsitute
y=x-3
y=-2/5-3
y=-3 and 2/5 or -17/5
the solution is (-2/5, -17/5)
there is only one solution
the answer is B

ANSWERED AT 18/01/2020 - 12:36 PM


QUESTION POSTED AT 18/01/2020 - 12:36 PM

The solution is n = –2 verified as a solution to the equation 1.4n + 2 = 2n + 3.2. What is the last line of the justification? A. 0.8 = 0.8 B. –0.8 = –0.8 C. 3 = 3 D. –3 = –3

we have

1.4n + 2 = 2n + 3.2

we know that

If n=-2 is a solution of the equation

then

the value of n must satisfied the equation

Substitute the value of n in the equation

1.4*(-2) + 2 = 2*(-2) + 3.2

-2.8 + 2 = -4 + 3.2

-0.8 = -0.8 ----> the equation is true

so

The value of n is a solution of the equation

therefore

the answer is the option B

-0.8 = -0.8


ANSWERED AT 18/01/2020 - 12:36 PM


QUESTION POSTED AT 18/01/2020 - 12:36 PM

Laurie is trying to stay within 10 feet of her current diving depth of –30 feet (with regard to sea level) so that the light is still good but she can be close to the sea life during her scuba dive. Which two equations can be used to find the minimum and maximum depths Laurie wants to stay between? A. x + 30 = 10 and x + 30 = –10 B. x – 30 = 10 and x – 30 = –10 C. x + 10 = 30 and x + 10 = –30 D. x – 10 = 30 and x – 10 = –30

ANSWER
A. x + 30 = 10 and x + 30 = –10

EXPLANATION
If x represents the depth of Laurie at a given moment, then the distance between his current depth and -30 feet is given by

   | x - (-30) |

which can be simplifed into

   | x + 30 |

We use absolute value because distance cannot be negative.

Laurie must stay within 10 feet. Therefore, the distance x is from -30 feet has to be equal to 10 to find the maximum and minimum depths that Laurie can stay between:

   | x + 30 | = 10

When we solve this absolute value equation, we work with two cases.

Case 1: When x + 30 is positive, then |x+30| = x+30 (no change) and we have the equation
   x + 30 = 10

Case 2: When x + 30 is negative, then |x+30| = -(x+30) so as to force the distance into a positive number. Then this gives us the equation
   -(x+30) = 10
which we can multiply both sides by -1 to get
   x + 30 = -10

ANSWERED AT 18/01/2020 - 12:35 PM


QUESTION POSTED AT 18/01/2020 - 12:35 PM

A line contains the point (0, –2). If the slope of the line is m= - 6 write the equation of the line using slope-intercept form.

Y = -6x-2
since -2 is the y intercept

ANSWERED AT 18/01/2020 - 12:35 PM


QUESTION POSTED AT 18/01/2020 - 12:35 PM