factorize 2x+4y+x^3+8y^3
回答 (3)
2007-10-04 7:40 pm
✔ 最佳答案
2x + 4y + x^3 + 8y^3= 2x + 4y + ( x + 2y )( x^2 - 2xy + 4y^2)
= 2( x + 2y ) + ( x + 2y )( x^2 - 2xy + 4y^2)
= ( x + 2y ) [ 2 + ( x^2 - 2xy + 4y^2) ]
= ( x + 2y ) ( x^2 - 2xy + 4y^2 + 2 )
2007-10-04 11:45:16 補充：
利用恆等式 a^3 + b^3 ≡ ( a + b )( a^2– ab + b^2 )
2007-10-04 8:06 pm
since a3 + b3 = (a+b) (a2 -2ab +b2)
therefore 2x+4y+x3+8y3
= 2x+4y+x3+(2y)3
= 2x+4y+(x+2y)(x2-2xy+4y2)
=(x+2y)(x2-2xy+4y2+2)
therefore 2x+4y+x3+8y3
= 2x+4y+x3+(2y)3
= 2x+4y+(x+2y)(x2-2xy+4y2)
=(x+2y)(x2-2xy+4y2+2)
2007-10-04 7:37 pm
2x+4y+x^3+8y^3
= 2(x+2y) + (x+2y)(x^2-2xy+4y^2)
= (x+2y)(x^2-2xy+4y^2+2)
= 2(x+2y) + (x+2y)(x^2-2xy+4y^2)
= (x+2y)(x^2-2xy+4y^2+2)
收錄日期: 2021-04-30 22:08:25
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