Question

What is the equation of the line that is the perpendicular bisector of the segment

with (10,-15) and (-10, 25) as endpoints?
y= kx + 10
y= kx + 5
y= -x + 10
y = 2x + 5

Answer 1

• y= kx + 5

Explanation:

Perpendicular bisector passes through the midpoint of the line.

The midpoint is:

• x = (10 - 10)/2 = 0
• y = (-15 + 25)/2 = 5

Slope of the line:

• m = (25 - (-15))/(-10 - 10) = -2

The line perpendicular to this has to have a slope of 1/2 as perpendicular lines have opposite-reciprocal slopes.

Use point-slope form and point (0, 5) to find the equation of the line:

• y - 5 = 1/2(x - 0)
• y = 1/2x + 5

Correct option seem B as others don't match ours