Please help! thank you!

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?

For a function f(x), a) if f(7) = 22 then f^-1(22) = b) f^-1(f(c)) =