Final answer:
To find f(g(x)), substitute g(x) into f(x) and simplify.
Step-by-step explanation:
To find the composite function f(g(x)), we substitute the expression for g(x) into f(x) and simplify.
f(x) = 5x + 15
g(x) = 2x² + 4x - 3
Substituting g(x) into f(x):
f(g(x)) = 5(2x² + 4x - 3) + 15
f(g(x)) = 10x² + 20x - 15 + 15
f(g(x)) = 10x² + 20x
Therefore, f(g(x)) = 10x² + 20x in standard form.