## ineedyouubiebs 2 years ago Write an equation for a line parallel to x+15=-5y passing through (0,4)

1. twinkieexpress

first put equation into y=mx+b then use point slope form y-y1=m(x-x1) m=slope

2. twinkieexpress

0=x1 4=y1

3. ineedyouubiebs

then the expression will look like y-4+m(x-0)

4. ineedyouubiebs

@twinkieexpress ?

slope will be -1/5 as it is parallel to the rrquired eqn.so slopes of oth equations wll be same.

u r given a point (0,4) this will be x1 and y1 in the eqn, (y-y1)=slope(x-x1) put the values and try it

7. ineedyouubiebs

How did you figured out the slope was -1/5?

8. eddy1120

First substitute the value to make y positive: y=-0.2x-3 then use the gradient equation: (y-y1)=m(x-x1) where m is the slope and the point is (x1,y1) and you will get this: y-4=-0.2(x-0) and after simplifying you get: y=-0.2x+4

9. eddy1120

because the slope on the x value is -1/5 when the coefficient of y is 1

10. ineedyouubiebs

@jim_thompson5910 ?

11. jim_thompson5910

what's the slope of x+15=-5y

12. ineedyouubiebs

1

13. jim_thompson5910

you need to get the equation into y = mx+b form first

14. ineedyouubiebs

is it y=1/5x+15

15. jim_thompson5910

close, but no

16. ineedyouubiebs

umm can you help me with it, y intercept form was a sucky thing for me

17. jim_thompson5910

start with x+15=-5y and divide both sides by -5 to isolate y

18. jim_thompson5910

what you have is close, but it's a bit off

19. ineedyouubiebs

umm 7=x-3

20. jim_thompson5910

hmm how are you getting that?

21. ineedyouubiebs

umm im trying to divide andthen divide both sides by -5

22. jim_thompson5910

another way to think about it: divide every term by -5 to isolate y

23. ineedyouubiebs

-1/5-3=y

24. jim_thompson5910

getting closer

25. ineedyouubiebs

ugh

26. jim_thompson5910

you lost x

27. ineedyouubiebs

y=1/5x-3

28. jim_thompson5910

it should be -1/5x - 3 = y

29. jim_thompson5910

much better

30. jim_thompson5910

oh sry

31. jim_thompson5910

it should be y = -1/5x - 3 but you pretty much have it (ignoring the typo)

32. ineedyouubiebs

and whats my next step?

33. jim_thompson5910

so what is the slope of y = -1/5x - 3

34. ineedyouubiebs

-1/5

35. jim_thompson5910

so the slope of any parallel line to this one is also -1/5

36. jim_thompson5910

since parallel lines have equal slopes

37. jim_thompson5910

the given point is (0,4) so x = 0 and y = 4 -------------------- we know that m = -1/5, x = 0, y = 4 plug these 3 pieces of info into y = mx + b and solve for b

38. ineedyouubiebs

y=1/5x+4

39. jim_thompson5910

the slope is negative, so it should be y = -1/5x + 4