Function Notations
Given
f(x) = 2x-7
g(x) = x^2 + x
Find: g(f(x))- I think I have the wrong answer, that is probably why I am confused out of my mind :S.
Please help me with full steps. :)

Question

Function Notations
Given 
f(x) = 2x-7
g(x) = x^2 + x
Find: g(f(x))- I think I have the wrong answer, that is probably why I am confused out of my mind :S.
Please help me with full steps. :)

anonymous · Answer

g(f(x))=(f(x))^2+f(x)= (2x-7)^2+2x-7=4x^2-26x+42

anonymous · Answer

$$f(x) = 2x - 7$$
$$g(x) = x^2 + x$$

Substituting

$$g(f(x)) = (2x - 7)^2 + (2x - 7)$$
Expanding

$$g(f(x)) = 4x^2 - 28x + 49 + 2x - 7$$

Simplifying

$$g(f(x)) = 4x^2 - 26x + 42$$

:)