how would i do number 2?

Answer:
m=2
Step-by-step explanation:
When you put a number into the inverse of a function (f^-1) you get the original number back.
Ex: f^-1(11) = (11-3)/2 = 4
f(4) = 2×4+3 = 11
So, f(-5)=-2
So, when x is -5,
f(x) = -2
f(x)=m(-5)+8
-2=m(-5) + 8
m=2