Question

If
f(x) = 2x² - 5
and
g(x) = 5x + 7
Find
f(g(x)) = [?]x² + [?]x + [?]

Answer 1

f(g(x)) = 50x² + 140x + 93

Explanation:

f(g(x)) means that within the f(x) equation, you want to replace all of the x variables with the g(x) equation.

So,

f(g(x)) = 2 (5x+7)² -5

= 2 ( 25x²+ 70x + 49) - 5

= 50x² + 140x + 93

:)