Question

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

Answer 1

$f(x)=-4x+7\\ g(x)=10x-6\\\\\Substitute\ x=10x-6\ to\ f(x)\\ f(g(x))=-4(10x-6)+7\\ f(g(x))=-40x+24+7=-40x+31\\\\\ Solution\ is\ f(g(x))=-40x+31.$