## drakelovermel 3 years ago Write the equation of the line that is perpendicular to the line 3x + y = 7 and passes through the point (6, -1).

1. waheguru

Do you know how to solve this?

2. drakelovermel

nooo im soo lost

3. waheguru

What don't you understand

4. drakelovermel

i dont understand how to solve it. its been a long time since i did algebra and i cant remember how to do it

5. waheguru

Lets Do this step by step Do you know parallel and perpendicular lines ? And how the slope change in relation to each

6. waheguru

When a line is parallel to a line then the slope stays the same |dw:1343935655688:dw| Here as you can see the lines will never meet because the slopes are the same althought the y intercepts can be different, even if the slopes were 2 for the first line and 1.9 for the second they wound not be parallel *When a line is parallel to another line the slope is the same Perpendicular lines intersect at 90 degrees and for that to happend the slope must be the opposite reciprocal so if a line is parallel to 1/2, we find the reciprocal which is 2/1 and change it from a positive to negative so it becomes -2/1 Do you get this much

7. waheguru

Sorry I meant to say when a line is perpendicular for the second paragraph

8. drakelovermel

yes

9. drakelovermel

oh okay

10. waheguru

3x + y = 7 Here you need to find the equation of the line which is perpendicular to this equation so right of the bat we need to make this in to y=mx+b format right so we can get the slope Do you know how to change it in to y=mx+b format?

11. waheguru

Convert 3x + y = 7 in to y=mx+b @drakelovermel

12. drakelovermel

i sorta forgot. please refresh my memory

13. waheguru

This is algebra 3x + y = 7 you need to isolate y amd move everythin g on the right side y=-3x+7

14. waheguru

Do you understand

15. drakelovermel

yes

16. waheguru

Now what is the perpendicular slope to -3x?

17. drakelovermel

was it y=3x+7

18. waheguru

No we moved it so it became negative

19. drakelovermel

ohh okay i got you

20. waheguru

So...

21. drakelovermel

okay so whats to learn next?

22. waheguru

What is the perpendicular slope to -3x.

23. drakelovermel

heyy thanks for the help! you where very helpful but i have to go eat and my mom is calling me soo im soo srry but i got to go. but thanks!!!

24. waheguru

Np!

25. jcyogi
26. drakelovermel

thank you soo much!