Question

If f(x)= x2 + 7; Find x if f(x)= 23

Answer 1

x = 4, -4

Explanation:

f(x)= x^2 + 7

f(x) =23

23 = x^2+7

Subtract 7 from each side

23-7 = x^2 +7-7

16 = x^2

Take the square root of each side

±sqrt(16) = sqrt(x^2)

±4 = x