## anonymous one year ago Help!

1. anonymous

1/3x+ 1/3 (2x-15) =3 1/2

2. Jhannybean

That's much better.

3. anonymous

@Emeyluv99

4. anonymous

now where were we.

5. anonymous

$$(3(2x-15) 1 + (3(2x-15)) (3x) \frac{1}{(3(2x-15))} = (3(2x-15)) (3x) \frac{7}{2}$$

6. anonymous

At the second denominator.

7. anonymous

yes, so when we multiply by the second denominator, we get ^^ that mess up there

8. anonymous

so lets simplify the second equation when the (3(2x-15)) cancels itself out

9. anonymous

$$(3(2x-15)) 1 + (3x) 1 = (3(2x-15)) (3x) \frac{7}{2}$$

10. Jhannybean

Original question: $\sf \frac{1}{3x}+\frac{1}{3(2x-15)}=\frac{7}{2}$

11. anonymous

@Emeyluv99

12. anonymous

oh my, it does

13. anonymous

it'll be worth it in the end! lets finish off the last denominator! 2!

14. anonymous

15. anonymous

$$2(3(2x−15))1+2(3x)1=2(3(2x−15))(3x) \frac{7}{2}$$

16. anonymous

Nice anime pic x'3

17. anonymous

that pic is awesome by the way

18. anonymous

Mys is loves drawing like you and ok.

19. anonymous

my sis*

20. anonymous

so simplify the problem out: 6(2x-15) + 6x = 9x(3x-15)

21. anonymous

Wait, I thought x's were out?

22. anonymous

no not yet, because we had to multiply by the denominators and the denominators had x's in them

23. anonymous

its our job now to get rid of them.

24. anonymous

and its quite easy too, no calculator required! watch!

25. anonymous

6(2x-15) + 6x = 9x(2x-15) 6(2x-15) - 9x(2x-15) = -6x <- I just switched the places of 9x(2x-15) and 6x, because now i can use the ax+bx = (a+b) x rule.

26. anonymous

Following so far.

27. anonymous

Can we eliminate x's now?

28. anonymous

so that would give you (2x-15)(6-9x) = -6x

29. anonymous

to basically, what we have now on the left side is a factored quadratic.

30. anonymous

To baically? What?

31. anonymous

sorry, SO, we have a factored quadratic on the left. which equates to -6x.

32. anonymous

K.

33. anonymous

what you have to do now is expand the quadratic on the left which will give you $$147x-18x^2-90=-6x$$

34. anonymous

then you get rid of -6x by adding 6x to both sides: $$147x-12x^2-90=0$$

35. anonymous

then you factor it again. ...

36. anonymous

Session expired. :( It's OK though, you have some physics right? :)

37. anonymous

ugh hang on, we mustve done somehting wrong... im getting radicals

38. anonymous

ill get back to you later, i have some homework to do... is that ok?

39. anonymous

It's fine. I could try to help if you want.

40. anonymous

im writing a lab up so its fine... thanks tho!