Penny solved an equation by subtracting 6 from each side of the equation and then dividing each side by 5.

Step-by-step explanation:

In order to solve for x, she had to first subtract 6 on both sides of the equation.  Then divide by 5 on both sides of he equation.  After the division part, she was able to successfully isolate x.

The equation she had to solve was     (C)  5x+6=21

First step:  Subtracting 6 on both sides of equation resulted in

5x = 15

Second step:  Dividing both sides of the equation by 5 resulted in

x = 3

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x