2007-10-31 04:21:59 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
(x/3 + 3/4) (3x/4 - 3/5)
= (4x + 9) (15x -12)
12 20
= (60x^2 -48x + 135x -108) /240
= (60x^2 + 87x -108) / 240
= (30x^2 + 29x - 36) /80
2007-10-31 04:30:03 · answer #1 · answered by naive 2 · 0⤊ 0⤋
(x/3 + 3/4)(3x/4 - 3/5)
(4x/12 + 9/12)(15x/20 - 12/20): Find common denominators
{(4x + 9)/12}{(15x - 12)/20}: Add fractions
(60x^2 - 48x + 135x - 108)/240: Multiply terms
(60x^2 - 87x - 108)/240: Add middle terms
(20x^2 - 29x - 36)/80: Reduce fraction by common term of 3
2007-10-31 11:36:01 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Basically take it step by step and times the denominators like this
(*3) (x/3+3/4)(3x/4-3/5)
(x+9/4)(9x/4-9/5)
(*4) (4x+9)(9x-36/5)
(*5) (20x+45)(45x-36)
900x^2 + 2020x + 720 -1620
900x^2 +2740 - 1620
I think that is the right answer :)
2007-10-31 11:33:16 · answer #3 · answered by knights_in 3 · 0⤊ 0⤋
(1/3*x +3/4)(3/4*x-3/5)=
(1/3)(3/4) x*x +[(3/4)(3/4)-(1/3)(3/5)] x -(3/4)(3/5)
2007-10-31 11:29:33 · answer #4 · answered by Nick 2 · 0⤊ 1⤋
(3x^2/12)+(87x/240)-(9/20)
then just add them up and you'll get
(60x^2+87x-108)/240
That can be simplified but I don't have any paper near by to do it on so...
2007-10-31 11:38:47 · answer #5 · answered by Anonymous · 0⤊ 0⤋