Please help me with a geometry problem, I don't understand.

Question

asked Dec 4, 2019 73.5k views

1 Answer

Keyana · Answer 1 · 2019-12-08T07:38:02+0000

The slope-intercept form:

$y=mx+b\\\\m=(y_2-y_1)/(x_2-x_1)$

m - slope

b - y-intercept

We have the points (1, -5) and (9, 11). Substitute:

m=(11-(-5))/(9-1)=(16)/(8)=2

Therefore we have

y=2x+b

Put the coordinates of the point (1, -5) to the equation:

$-5=2(1)+b\\\\-5=2+b\qquad\text{subtract 2 from both sides}\\\\-7=b\to b=-7$