Question

Three algebra 1 questions.

Answer 1

$1.\\g(x)=x+10\to g(0)=0+10=10\\\\f(x)=3x\to f(g(0))=f(10)=3\cdot10=30$

$2.\\g(x)=x+12\\f(x)=4-2x\to f(g(x))=4-2(x+12)=4-2x-24=-2x-20$

$3.\\y=9x+15\ \ \ |-15\\9x=y-15\ \ \ |:9\\\\x=\dfrac{y-15}{9}$
Answer:   $y=\dfrac{x-15}{9}=\dfrac{1}{9}x-\dfrac{5}{3}$