Geometry test for today pls help

Question

A. Find the coordinates of J if M(-2, 1) is the midpoint of JL and L(-7, 2)

B. Use the coordinates for J and L to find the distance of JL.

Answer 1

midpoint (x,y) = (x1 + x2)/2, (y1 + y2)/2

=-2,1 = (x1 + -7)/2, (y1 + 2)/2

-2 = (x1 - 7)/2 1 = (y1+2)/2

-4 = x1 - 7 2 = y1 + 2

3 = x1 0 = y1

coordinate of J is (3,0)

coordinate of L is (-7,2)

distance between (x1,y1) and (x2,y2)

= sqrt ( (y2-y1)^2 + (x2-x1)^2)

distance = sqrt( (2-0)^2 + (-7-3)^2) = sqrt(4+100) = sqrt(104) = 10.2