Question

Paul wants to write equations in the form y=mx+b
for the lines passing through point D
that are parallel and perpendicular to line h
. First he finds the slopes of these two lines. What could he do next to find the y
-intercepts?

On a coordinate plane, lines g and h are parallel. Line f is perpendicular to both lines. Lines g and f intersect at point D.
CLEAR CHECK

Substitute the slope and the coordinates of point D
in y=mx+b
and then solve for b
for each equation.


Solve the proportion mb=yx
for b
.


Multiply the slope by the x
-coordinate and add the y
-coordinate to the product.


Multiply the slope by the y
-coordinate and subtract the result from the x
-coordinate.