Find all values of x such that (f o g)(x) = -4. Separate answers with a comma if necessary.

Question

 f(x) = 2 x - 4

g(x) = x^2 - 3 x + 2

Answer 1

f(g(x)) = -4

 

2(x²-3x+2) -4 = -4

 

x² - 3x + 2 = 0

 

(x - 2)(x - 1) = 0

 

x = 2, 1