Question

If f(x) = 2x - 3 and g(x) = (x + 7), then find f(g(x)). a) 2x + 4b) 2x + 11c) x + 11 d) 3x + 4

Answer 1

To find f(g(x)), we have to substitute the formula for g(x) as the input for f(x).

f( g(x) ) = f( x+7 )

= 2 (x+7) - 3

= 2x + 14 - 3

= 2x + 11

The key is to substitute the entire formula for g(x) in as the input for f.