multiply these fractions 2x^2 - x - 3 over 3x^ + 7x +4 times 3x^2-11x - 20 over 4x^2 - 9?

Question

these are really tough
Dividing looks even harder
6p- 18 over 9p divided by 3p - 9 over p^2 + 2p

Can any one help me with these two problems Can anyone email me to go over some more. I am really struggling with this class and need help

Answer 1

Factor them first, then the rest'll be much easier.

Lots will cancel out. :-)

(I know b/c I just did the problems, plus they always did when I took this in school way back as well)

If you need other help once you've factored it, let me know!

Hint: 2x^2 - x - 3 factors into (2x-3) (x+1)
Just factor each of your equations and you'll be pleasantly surprise how they just magically work out. Just be sure you've got the right pieces in the right place (numerator and denominator). In your case, it'd be


2x^2 - x - 3 3x^2-11x - 20
= --------------- X -------------------
3x^ + 7x +4 4x^2 - 9?


and for your 2nd problem, remember that

a
--
b a x d
---- = --------
c b x c
--
d

Answer 2

1(2x^2-x-3/3x^2+7x+4)(3x^2-11x-20/4x^2-9)
[2x(x-1)+3(x-1)/3x(x+1)+4(x+1)][3x(x-5)+4(x-5)/(2x+3)(2x-3)]
(x-1)2x+3)/(x+1)(3x+4)][x-5)(3x+4)/(2x+3()(2x-3)]
(x-1)(x-5)/(x+1)(2x-3)
2.6(p-3)/9p][p(p+2)/3(p-3)]
2(p+2)/9