Question

Find x given the function f(x)=4x-7 where f(x)=9

Answer 1

The answer is 4

Explanation:

f(x)=4x-7

f(x)=9

9=4x-7

9+7=4x-7+7

(the -7 and the +7 cancel out, and remember: whatever you do the one side you have to do to the other)

16=4x

(divide by 4 to isolate x and do the same to the other side of the equation so you get the answer)

so, x=4

Answer 2

4

Explanation:

You set f(x) = 9 and solve from there.

9 = 4x - 7

+7 +7

16 = 4x

/4 /4

x = 4