What is expanded notation math.

3× __ -2=15 7 2× __+1=7 5 7× =22 15 5× __+10=2 8 × __+4=20 6 × =10 3 × __+2=8 6 × __+8=8 9 × __+7=20 6

On the first of each month sasha runs a 5k race she keeps track of her times to track her progress her time in minutes is recorded in the table

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