Factor: 8a^3+(a+b)^3?
回答 (4)
2016-07-17 2:31 pm
Identity : a³ + b³ = (a + b)(a² - ab + b²)
8a³ + (a + b)³
= (2a)³ + (a + b)³
= [2a + (a + b)] [(2a)² - 2a(a + b) + (a + b)²]
= (2a + a + b)(4a² - 2a² - 2ab + a² + 2ab + b²)
= (3a + b)(3a² + b²)
8a³ + (a + b)³
= (2a)³ + (a + b)³
= [2a + (a + b)] [(2a)² - 2a(a + b) + (a + b)²]
= (2a + a + b)(4a² - 2a² - 2ab + a² + 2ab + b²)
= (3a + b)(3a² + b²)
2016-07-17 3:19 pm
This is the sum of two cubes.
(2a)³ + (a + b)³ = (2a + a + b)(4a² - 2a² - 2ab + a² + 2ab + b²) =
(3a + b)(3a² + b²)
(2a)³ + (a + b)³ = (2a + a + b)(4a² - 2a² - 2ab + a² + 2ab + b²) =
(3a + b)(3a² + b²)
2016-07-17 5:39 pm
8a^3 + (a + b)^3
= (2a)^3 + (a + b)^3
= (3a + b)(3a^2 + b^2)
= (2a)^3 + (a + b)^3
= (3a + b)(3a^2 + b^2)
2016-07-17 2:35 pm
(2a)^3 + (a+b)^3
x^3+y^3 = (x+y)(x^2-xy+y^2)
x= 2a
y = a+b
8a^3 + (a+b)^3 = (2a+a+b) ( 4a^2-2a(a+b) + (a+b)^2) )
= (3a+b) (4a^2 -2a^2-2ab +a^2+b^2+2ab)
= (3a+b) (3a^2+b^2)
x^3+y^3 = (x+y)(x^2-xy+y^2)
x= 2a
y = a+b
8a^3 + (a+b)^3 = (2a+a+b) ( 4a^2-2a(a+b) + (a+b)^2) )
= (3a+b) (4a^2 -2a^2-2ab +a^2+b^2+2ab)
= (3a+b) (3a^2+b^2)
收錄日期: 2021-05-01 14:09:47
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