2007-03-31 04:16:17 · 6 answers · asked by aceofhearts0004 2 in Science & Mathematics ➔ Mathematics
Sum and difference of two cber
a³ - b³ =
(a - b)(a² + ab + b²)
- - - - - - - - -
x³ - 8 =
(x - 2)(x² + 2x + 4)
- - - - - - - - - -s-
2007-03-31 06:30:18 · answer #1 · answered by SAMUEL D 7 · 0⤊ 0⤋
The first is a difference of cubes, the second is a difference of squares.
a^3 - b^3 = (a-b)(a^2 + ab + b^2)
use a = x (then a^3 = x^3)
and b = 2 (then b^2 = 8)
a^2 - b^2 = (a+b)(a-b)
use a= 2 (then a^2 = 4)
and b=5x (then b^2=25x^2)
2007-03-31 11:20:32 · answer #2 · answered by Raymond 7 · 1⤊ 0⤋
That's pretty easy....
just look
(x^3-8) can be factorized with (a^3-b^3)and that would be...
(x-2)(x^2+2x+4) and (4-25x^2)that can be factorized with the identity(a^2-b^2)
(2-5x)(2+5x) that it!
Thanks and good luck
2007-03-31 11:22:41 · answer #3 · answered by The Subtle Kind 3 · 1⤊ 0⤋
hi,
a^3 -b^3 = (a-b)(a^2 +b^2 +ab)
therefore x^3 -8 = x^3 -2^3 = (x- 2)(x^2 +2^2 +2x) = (x-2)(x^2 +4+2x)
here i have susbstituted a = x , b =2 in the formula.
a^2-b^2 = (a+b)(a-b)
there fore 4 -25x^2 = 2^2 -(5x)^2 = (2+5x)(2-5x)
a = 2 , b =5x.
2007-04-04 03:56:18 · answer #4 · answered by valivety v 3 · 0⤊ 0⤋
x^3-8= (x-2)3
4-25x^2= (2+5x)(2-5x)
2007-03-31 11:20:12 · answer #5 · answered by shawn michaels pwns cena 4 · 1⤊ 0⤋
1.x^3-8
(x-2)(x^2+2x+4)
2.4-25x^2
(2+5x)(2-5x)
2007-03-31 11:22:53 · answer #6 · answered by Anonymous · 0⤊ 0⤋