Help? Can it be step by step. I got a quiz tomorrow and need some help please

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

Square a has a side length of (2x-7) and square b has a side length of (-4x+18). how much bigger is the perimeter of square b than square a?and show all work! you so

Triangle xyz, with vertices x(-2, 0), y(-2, -1), and z(-5, -2), undergoes a transformation to form triangle x? y? z? , with vertices x? (4, -2), y? (4, -3), and z? (1, -4). the type of transformation that triangle xyz undergoes is a . triangle x? y? z? then undergoes a transformation to form triangle x? y? z? , with vertices x? (4, 2), y? (4, 3), and z? (1, 4). the type of transformation that triangle x? y? z? undergoes is a .