## Steph_Rawr352 3 years ago Check my answer? Write the equation of the line passing through point (2,-3) and is perpendicular to y=4x+7 in standard form. I got 4x+y=-11; is it right?

1. hartnn

no again...

2. hartnn

slope of given line ?

3. Steph_Rawr352

4

4. hartnn

yes, so slope of perpendicular line ?

5. Steph_Rawr352

4/1 ?

6. hartnn

the product of slope of perpendicular lines = -1

7. hartnn

so m1 * m2 = -1 m1 = 4, m2= ?

8. Steph_Rawr352

oh 4!

9. Steph_Rawr352

10. hartnn

no, slope of perpendicular line will be negative *reciprocal*

11. hartnn

so m1*m2 = -1 4m2=-1 m2 = -1/4 ok ?

12. Steph_Rawr352

ohk sorry I'm not really good at this I just learned this

13. hartnn

so now u have slope of required line and a point on it, which equation will u use ?

14. Steph_Rawr352

point-slope form? y-y1=m(x-x1)

15. hartnn

thats correct! so what u get ?

16. Steph_Rawr352

y-(-3)=-1/4(x-2) ?

17. hartnn

correct :) now simplify....

18. Steph_Rawr352

y-(-3)=-1/4x - idk/: 0.5?

19. hartnn

(-1/4)(-2) = +2/4 = +0.5

20. hartnn

y-(-3) = y+3

21. Steph_Rawr352

oh wait.. y+3 = -1/4x - 0.5 then would you add -1/4x to the left side? since I have to write it in standard form? ax+by=c?

22. hartnn

1) its y+3 = -1/4x + 0.5 2) yes., add 1/4 x , not -1/4 x

23. Steph_Rawr352

ohk so .. 1/4x+y+3=0.5 then add subtract 3 on both sides?

24. hartnn

yes, correct

25. Steph_Rawr352

1/4x+y=2.5

26. hartnn

0.5-3 = -2.5

27. hartnn

or u could first multiply by 4 on both sides

28. Steph_Rawr352

oh yeah.. sorry.. and oh ohk if i did that it would be x+y=2

29. hartnn

let me show you steps: y+3 = -1/4x + 0.5 y+1/4 x +3= 0.5 multiplying 4 on both sides 4y+ x + 12 = 2 now can u solve ahead

30. Steph_Rawr352

4y+x=14

31. hartnn

2-12=?

32. Steph_Rawr352

oh whoops -10

33. hartnn

you will subtract 12 from both sides, right ?

34. Steph_Rawr352

yes, sorry

35. hartnn

so finally, 4y+x=-10

36. Steph_Rawr352

yeah thank you though! (:

37. hartnn

welcome ^_^