## anonymous 2 years ago Help! The question is attached!

1. anonymous

Attempt to solve for x! (4,y) and (7,-6); slope:-4

2. anonymous

$\frac{ -6-y }{ 7-4 }=-4$ $\frac{ -6-y }{ 3 }=-4$ I just set it up like the normal slope equation, (y2-y1)/(x2-x1). Now just see if you can solve for y.

3. anonymous

Olay, let me try it out for myself to see if I understand it

4. anonymous

Alrighty.

5. anonymous

Wait, I get -6 / 3 how did you get -4?

6. anonymous

You said the slope = -4, right? Well, the result of (y2-y1)/(x2-x1) is slope. But we already have the slope, so I just set the equation equal to -4.

7. anonymous

Ahhhhhh okay I see how you set it up!

8. anonymous

And then you subtract the bottom, correct?

9. anonymous

Yeah, which left me with $\frac{ -6-y }{ 3 }=-4$Would you know how to use that to solve for y?

10. anonymous

My guess is that I multiply -6 and 3

11. anonymous

Just multiply both sides by 3 to start.

12. anonymous

That will cancel the 3 out of the denominator of the fraction.

13. anonymous

So would it be 18+3y=-4

14. anonymous

Nah. Okay, so we multiply both sides by 3 and it looks liek this: $\frac{ 3(-6-y) }{ 3 }=-4(3)$From here, the 3's on the left cancel out and -4 and 3 multiplies to get: $-6-y = -12$ Kinda see why?

15. anonymous

Yea aha I sorta do, it's because I got -18-3y=-12 when I multiplied it by 3

16. anonymous

Yeah, but you dont multiply the -6 and the -y by 3. Because you have a 3 on top and bottom, they cancel out and become 1. That is the whole purpose of multiply by 3 is because itll get rid of the denominator. It's just like if we had: $\frac{ x }{ 3 }=3$Because x is divided by 3, to get it by itself we do the opposite operation and multiply by 3. |dw:1378605836732:dw| Same thing with our problem: |dw:1378605874087:dw|

17. anonymous

Ahhhhhh okay I see now! And then after I get -6-y=-12 I add 6 to both sides

18. anonymous

Right.

19. anonymous

When I divide y to both sides, would I be dividing -y or just y?

20. anonymous

Well if you have -y = -6, it does no good to divide by y or -y. If you divided by -y you get: $1=\frac{ 6 }{ y }$ You just want to divide by -1 is all to get y by itself.

21. anonymous

And the final answer will be y=6

22. anonymous

Bingo. Can even test it :3 $\frac{ -6-6 }{ 7-4 }=\frac{ -12 }{ 3 }=-4$ So yep, works :3

23. anonymous

Thank you much, you explained very well unlike most people here :D do you have time to help me with another 3 problems I had trouble with?