If the midpoint between (18, y) and (20, -15) is (19, -5), find the value of y.

Question

im doing homework

Answer 1

Say the points   (x1,y1) = (18,y)

(x2,y2) = (20,-15)

Mid point of given points = [(x1+x2)/2, (y1+y2)/2]

(19,-5) = [(18+20)/2, (y-15)/2]

(19,-5) = [(38/2,(y-15)/2]

(19,-5) = [19,(y-15)/2]

(y-15)/2 = -5

Multiple to each side by 2.

2(y-15)/2 = -5*2

y-15 = -10

Add 15 to each side.

y+15-15 =-10+15

⇒ y = 5