I have to factor these problem completly
b^2 - ab - 6a^2 ???
and
25x^2 -9 ????
Also I am having trouble understanding factoring by grouping with this problem
6x^3 + 21x62 - 2x - 7
HELP
2007-02-05 12:22:42 · 3 answers · asked by CookFrNW 3 in Science & Mathematics ➔ Mathematics
b^2 - ab - 6a^2
=(b-3a)(b+2a)
25x^2 -9
=(5x-3)(5x+3)
6x^3 + 21x^2 - 2x - 7
=2x(3x^2-1)+7(3x^2-1)
=(2x+7)(3x^2-1)
2007-02-05 12:27:33 · answer #1 · answered by A 150 Days Of Flood 4 · 0⤊ 0⤋
25x^2 - 9
(5x+3)(5x-3)
x = -3 / x = 3
2007-02-05 20:27:03 · answer #2 · answered by Aaron 4 · 0⤊ 0⤋
first one =(b-3a)(b+2a)
second one=(5x-3)(5x+3)
third:?(I guess you meant 6x^3+21x^2-2x-7)? in that case
=(3x^2-1)(2x+7)=((3^1/2)x+1)((3^1/2)x-1)(2x+7)
2007-02-05 20:50:58 · answer #3 · answered by alirezamortezai 2 · 0⤊ 0⤋