Question

If the distance between two points ( x , 7 ) and (1, 15) is 10, find x.

Answer 1

Here x1 = x, y1 = 7, x2 = 1 and y2 = 15

=> sqrt [ (x-1)^2 + (7-15)^2] = 10

take square of both the sides
=> (x-1)^2 + (7-15)^2 = 100
=> (x-1)^2 + 64  = 100

subtract 64 from other the sides.
=> (x - 1)^2 = 100-64
=> (x - 1)^2 = 36

take the square root
=> x-1 = 6 or x -1 = -6
=> x = 7 or x = -5

Therefore x can be either -5 or 7.