How do you find the distance between (-40,-120) and (-90,60) ?

There are two ways:

One if you have a graphing calculator (TI-84 plus) you can go to stat then edit then type in the - 40 and - 90 on the left and the - 120 and 60 on the right. The press stat again and go to the right to calc the down to linreg (ax + b) and go down to calculate amd press enter.

Your answer is y = - 3.6x+-264

option two is by hand

the formula is y1-y2 divided by x1-x2