Something about a^3 + b^3 factors into something else...
2007-07-25 12:35:26 · 6 answers · asked by Like Woah 3 in Science & Mathematics ➔ Mathematics
a^3 + b^3 = (a+b)(a^2 - ab + b^2)
a = 2x, b = 3y.
(2x+3y)(4x^2 - 6xy + 9y^2)
2007-07-25 12:40:24 · answer #1 · answered by holdm 7 · 0⤊ 0⤋
sum of perfect cubes formula
a^3 + b^3 = (a + b) (a^2 - ab + b^2)
8x^3 + 27y^3
2^2 x^3 + 3^3 y^3
= (2x)^3 + (3y)^3
use the formula above you'll get:
(2x + 3y) (4x^2 - 6xy + 9y^2)
2007-07-25 12:40:28 · answer #2 · answered by 7 · 0⤊ 0⤋
that is (2x+3y)(4x^2 - 6xy + 9y^2)...
you take the cubical root (I dont know how to say it in english)of 8x^3 and the cubical root of 27y^3 and then in another parenthesis you put the 1st one^2 then if the 2nd one is possitve then you put it negative and then you multiply the first one with the second one, then the square root of the second one (possitive)!!
2007-07-25 12:44:11 · answer #3 · answered by Josesito 1 · 0⤊ 0⤋
8x^3 + 27y^3 = 2^3Ã x^3 + 3^3 Ã y^3
= (2x)^3 + (3y)^3..
Hope i helped...
2007-07-25 12:46:36 · answer #4 · answered by Anonymous · 0⤊ 0⤋
That's a perfect cube. (A + B)(A² â AB + B²)
(2x + 3y)(4x^2 - 6xy + 9y^2)
2007-07-25 12:41:06 · answer #5 · answered by tkquestion 7 · 0⤊ 0⤋
(2x + 3y)(4x^2 - 6xy + 9y^2)
2007-07-25 12:41:00 · answer #6 · answered by S M 2 · 0⤊ 0⤋