How would I go about doing this, and am I supposed to divide...
Here's the problem written out:
3x^2 - 6x - 45
__________
x^2 - 25
2007-11-05 08:12:05 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
3x^2 - 6x - 45 / x^2 - 25
3x^2 - 6x - 45 = (x - 5) (3x + 9)
x^2 - 25 = (x - 5) (x + 5)
= (x - 5) (3x + 9)/(x - 5) (x + 5)
= (3x + 9)/ (x +5)
= 3 (x + 3)/(x + 5)
2007-11-05 08:22:45 · answer #1 · answered by Shh! Be vewy, vewy quiet 6 · 0⤊ 2⤋
The easiest way to do these types of problems is assuming that the numerator will have one of the factors of the denominator. So, factoring the denominator you would get (x+5)(x-5). So, take (x-5) and try to find something multiplied by this that would give the numerator, in this case (3x+9)*(x-5) = 3x^2 - 6x -45.
So, simplified the answer would be (3x+9)/(x+5).
2007-11-05 08:20:12 · answer #2 · answered by rahl13_13 1 · 0⤊ 1⤋
N = 3 x ² - 6 x - 45
N = 3 (x ² - 2 x - 15)
N = 3 ( x - 5 ) ( x + 3 )
D = (x - 5)(x + 5)
N/D = 3 (x + 3) / (x + 5)
2007-11-05 09:28:43 · answer #3 · answered by Como 7 · 2⤊ 1⤋