For question # 3:
f(-3)=I-3I=3
f(-11)=(-11)^2=121
For question #4: to find the inverse, you replace the f(x) with x and replace the x with f(x), then solve for the new f(x)
Original: f(x)=3x+7
Change it into" x=3f(x)+7
solve for f(x): 3f(x)=x-7 => f(x)=(1/3)x -7/3
so the inverse is : f(x)=(1/3)x -7/3
