can someone pls help me find the gradient and y-intercept of the last 2 questions . tysm i will give brainliest !

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?

Factor the expression using gcf 9b+45

Simplify the expression below -3(10x+4y)+6(6x-2y)