Question

The perpendicular bisector of the line segment connecting the points $(-3,8)$ and $(-5,4)$ has an equation of the form $y = mx + b$. Find $m+b$.

Answer 1

m = -1/2 and b = 6.5

Explanation:

To find the slope of the original line segment, we have to do the change in y/the change in x:

(4-8)/(-5--3) = -4/-2 = 2

2 is the slope of the original line segment, but since this is the perpendicular bisector, we have to take the negative reciprocal of 2 so m = -1/2

To find b we substitute the values of x, y, and m into the equation. Let's use the x value of -3 and the y value of 8:

y = mx + b

8 = -1/2(-3) + b

8 = 3/2 + b

6.5 = b