Help me with this please

Find the average rate of change for f(x) = x2 − 3x − 10 from x = −5 to x = 10.

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

When a rectangle is dilated, how do the perimeter and area of the rectangle change?