Simplify and select the answer with the appropriate restrictions for the variable. will give brainliest answer.

[(x + 3) (x + 7)] / (3x + 21)

= [(x + 3) (x + 7)] / [3 (x + 7)]

= (x + 3) / 3

The denominator can't be equal to 0 therefore:

3 (x + 7) ≠ 0 ⇔ x + 7 ≠ 0 ⇔ x ≠ -7

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)

50x5=$250

step-by-step explanation: