Plz help asap almost done

Given: f(x) = 2x + 5 and g(x) = x2 and h(x) = -2x h(g(f( = x2+ vx+ x + y

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.