Question

Find the value of x so that the line passing through (10, 5) and (x, 9) has a slope of -2.

Answer 1

Ok, so here, we need to use the slope formula which is:

(y2 - y1)/(x2-x1)

y2 = 9
y1 = 5

x2 = x
x1 = 10

So:

(9-5)/(x-10) = -2

Now, we just solve for x,

9-5  =  -2(x-10)

4  =  -2x+20

2x  =  16

x  =  8

Answer 2

x=8 ....................