Which expression is equivalent to the distance between –13 and –4 on a number line?

Factor the expression using the gcf. the expression 21m−49n factored using the gcf

Aschool had an election where the candidates received votes in the ratio 1: 2: 3. if the winning candidate received 210 votes, how many total people voted in the election?

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