Simplify: -2 1/3 - (-10 1/6)

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.

Ten times the square of a non-zero number is eqaul to ninety times the number

Ineed the solution to this problem and the steps.