Question

Let f(x) = -4x + 7 and g(x) = 10x - 6, find f(g(x)).

Answer 1

\(\bf f(x) = -4x + 7\qquad {\color{red}{ g(x)}} = 10x
\\ \quad \\
f(\quad g(x)\quad )=-4({\color{red}{ 10x}}) + 7\)

Answer 2

Kidd: f(g(x)) is called a "composite function."

g(x) becomes the input to the other function, f(x).

Note how JDoe has replaced x within f(x) with g(x), on the left, and then replaced x with 10x, on the right. Just simplify the expression on the right and you'll have the appropriate expression for f(g(x)).