SOLUTION: Slope -3/7; through (7,0) I used the point-slope equation method to solve, but for some reason I am not understanding how to solve. I used y2-y1=m(x-x1) y-0=-3/7(x-7) y=-

Algebra ->  Graphs -> SOLUTION: Slope -3/7; through (7,0) I used the point-slope equation method to solve, but for some reason I am not understanding how to solve. I used y2-y1=m(x-x1) y-0=-3/7(x-7) y=-      Log On


   

Question 127431: Slope -3/7; through (7,0)
I used the point-slope equation method to solve, but for some reason I am not understanding how to solve.
I used y2-y1=m(x-x1)
y-0=-3/7(x-7)
y=-3/7.7/3 reciprocal
y=1x-7
The answer is supposed to be 3x+7y=21.
I have no idea how to get there.
Thank you.
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Well, you are correct...up to a point!
You are given the slope: m+=+-3%2F7 and a point (7, 0) and you wrote:
y-0+=+%28-3%2F7%29%28x-7%29 This is correct, so far. Now, it appears that you want the answer in standard form: ax%2Bby+=+c, so...
y+=+%28-3%2F7%29%28x-7%29 Distribute the -3%2F7 to get:
y+=+%28-3%2F7%29x+%2B+3 Then multiply through by 7.
7y+=+-3x%2B21 Now write this in standard form by adding 3x to both sides:
3x%2B7y+=+21