Question

help please!!! been stuck on this problem for a while (screenshot below)

Answer 1

@sleepyjess

Answer 2

@Hero

Answer 3

You are given two points on one of the lines, and are told that the two lines are parallel.
Find the slope of these lines (same slope for both).

Answer 4

Use the slope formula and the coordinates of the 2 given points.

Answer 5

ah okay and then what do i do?

Answer 6

Please find the slope now. Then we'll move on to the rest of this question.

Answer 7

@mathmale i got -1.4 as the slope

Answer 8

Very good. Lines AB and CD are parallel and thus have the same slope.

Choose either endpoint of AB and the slope you just found to find the equation of the line AB.

Answer 9

so y=mx+b?

Answer 10

Yes. y=-1.4x + b. You must find b.
You know the slope of this line, and you could pick either A or B as a point on the line. This is all the info you need to determine the y-intercept, b.

Answer 11

im rlly clueless how do i find B

Answer 12

You have already typed in y=mx+b. What is b? Choose one of the 2 end points and write out the x- and y- coordinates of that point. Substitute these 3 numbers into y=mx+b.

Answer 13

ah okay thanks!

Answer 14

My pleasure. Continue with this work, please.

Answer 15

suppose you choose endpoint B:(3,7). x=3 and y=7. m=-1.4.
Subst. these 3 numbers into y=mx+b and calculate b.

Answer 16

oh!!! i get it now

Answer 17

0.6?

Answer 18

and would -1.4 still be the slope? @mathmale