The midpoint of a line segment AB is (1, 2). Point A coordinates are (3, –3) and point B coordinates are (x, 7). Find the value of x

Answer 1

The midpoint formula is ( (x_1 + x_2) / 2 , (y_1 + y_2) / 2 ) ). Set this equal to (1, 2).

(1, 2) = ( (x_1 + x_2) / 2 , (y_1 + y_2) / 2 ) )

Substitute (3, -3) for x_1 and y_1 and (x, 7) for x_2 and y_2.

(1, 2) = ( (3 + x) / 2 , (-3 + 7) / 2 ) )

Solve for x using the midpoint x-coordinate of 1.

1 = (3 + x) / 2

Multiply both sides by 2.

2 = 3 + x

Subtract 3 from both sides.

x = -1