Question

Three algebra 1 questions.

1. Find f(g(0)) if f(x) = 3x and g(x) = x + 10

2. Find f(g(x)) if f (x) = 4 - 2x and g(x) = x + 12

3. Which expression represents the inverse of y = 9x + 15 ?

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=(y-15)/(9)`
Answer:
`y=(x-15)/(9)=(1)/(9)x-(5)/(3)`