and what about (9k^2-24)
2007-04-22 09:39:09 · 5 answers · asked by That guy 1 in Science & Mathematics ➔ Mathematics
x^2-25=x^2-5^2=(x+5)(x-5)
9k^2-24=(3k)^2-(2rt6)^2=(3k+2rt6)(3k-2rt6)
2007-04-22 09:45:27 · answer #1 · answered by raj 7 · 2⤊ 0⤋
You don't. If this is supposed to factor as a difference of two squares, then the square root of 3x² is xâ3.
3x² - 25 factors into (xâ3 + 5)(xâ3 - 5).
For 9k² - 24, you can factor out a GCF of 3.
9k² - 24 = 3(3k² - 8). If you have to factor it further, it would be
3(kâ3 + 2â2)(kâ3 - 2â2).
2007-04-22 16:45:56 · answer #2 · answered by Louise 5 · 1⤊ 1⤋
(x+5)(x-5) comes out to be
x^2 - 5x + 5x - 25
the 5x's take eachother out. -5 + 5=0
and the (9k^2-24) is
(3k + â24)(3k - â24)
2007-04-22 16:44:57 · answer #3 · answered by jessica 2 · 1⤊ 1⤋
You can't change 3x^2-25 to (x+5)(x-5), because this latter term multiplies out to equal x^2-25.
2007-04-22 16:43:38 · answer #4 · answered by bruinfan 7 · 1⤊ 1⤋
factoring
2007-04-22 17:44:51 · answer #5 · answered by verner66 2 · 1⤊ 1⤋