SOLUTION: I'm still having a ridiculous time with this problem. I don't know why I can't get this, even after reviewing my factoring notes. 3a-3y/3a-3y-ab+by * b^2-9/6b+18 3(a-y)/3(a-

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I'm still having a ridiculous time with this problem. I don't know why I can't get this, even after reviewing my factoring notes. 3a-3y/3a-3y-ab+by * b^2-9/6b+18 3(a-y)/3(a-      Log On


   

Question 234104: I'm still having a ridiculous time with this problem. I don't know why I can't get this, even after reviewing my factoring notes.
3a-3y/3a-3y-ab+by * b^2-9/6b+18
3(a-y)/3(a-y)+b^2(y-a) * (b+3)(b-3)/6(b+3)
b(y-a) * 1/2
1/2b (y-a)
I know the answer is -1/2, but I'm not sure why. This one's just really super tough for me for some reason! Thank you!
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
%283a-3y%29%2F%283a-3y-ab%2Bby%29 * %28b%5E2-9%29%2F%286b%2B18%29
:
%283%28a-y%29%29%2F%283%28a-y%29-b%28a-y%29%29 * %28%28b-3%29%28b%2B3%29%29%2F%286%28b%2B3%29%29
:
Factor out (a-y) in the denominator
%283%28a-y%29%29%2F%28%28a-y%29%283-b%29%29%29 * %28%28b-3%29%28b%2B3%29%29%2F%286%28b%2B3%29%29
:
Cancel (a-y) & (b+3)
3%2F%28%283-b%29%29%29 * %28%28b-3%29%29%2F6%29
:
Cancel 3 into 6
1%2F%28%283-b%29%29%29 * %28%28b-3%29%29%2F2%29
:
Use -1 to make (b-3)
1%2F%28-1%28b-3%29%29%29 * %28%28b-3%29%29%2F2%29
:
Cancel (b-3)
1%2F%28%28-1%29%29 * 1%2F2%29
:
-1 * 1%2F2 = -1%2F2