Answer:
[tex]f(x - 4) = x^2 - 6x+ 8[/tex]
Step-by-step explanation:
Given
[tex]f(x) = x^2 + 2x[/tex]
Required
Find f(x - 4)
Substitute x - 4 for x
[tex]f(x - 4) = (x- 4)^2 + 2(x - 4)[/tex]
Expand
[tex]f(x - 4) = x^2 - 8x + 16 + 2x - 8[/tex]
Collect like terms
[tex]f(x - 4) = x^2 - 8x + 2x+ 16 - 8[/tex]
[tex]f(x - 4) = x^2 - 6x+ 8[/tex]
