Question

If
M(2, 10)
is the midpoint of the line segment AB and if A has coordinates
(−3, −5),
find the coordinates of B.

Answer 1

midpoint = (x1 + x2) / 2, (y1 + y2) / 2
(-3,-5)....x1 = -3 and y1 = -5
(x,y)....x2 = x and y2 = y
now we sub
m = (-3 + x) / 2, (-5 + y) / 2 

(-3 + x) / 2 = 2
-3 + x = 2 * 2
-3 + x = 4
x = 4 + 3
x = 7 <==

(-5 + y) / 2 = 10
-5 + y = 10 * 2
-5 + y = 20
y = 20 + 5
y = 25 <==

so ur point B has coordinates (7,25)