过程最好也有）：若(C+2xy)(1/2ab+D)=4x^2 y^2-1/4a^2 b^2,则C+D=
问题描述：
过程最好也有）：若(C+2xy)(1/2ab+D)=4x^2 y^2-1/4a^2 b^2,则C+D=
答
(C+2xy)(1/2ab+D)=4x²y²-1/4a²b²=(2xy+1/2ab)(2xy-1/2ab)
假设C=-1/2ab那么D=2xy
C+D=2xy-1/2ab
假设C=1/2ab那么D=2xy-2/2ab
C+D=1/2ab+2xy-2/2ab=2xy-1/2ab
所以C+D=2xy-1/2ab
答
2xy-1/2ab
答
-1/2ab +2xy
初一数学题,应该刚接触平方差公式,根据公式套就行
答
因为4x^2y^2-1/4a^2b^2=(2xy+1/2ab)(2xy-1/2ab)
若C=-1/2ab，则D=2xy
C+D=2xy-1/2ab
若C=1/2ab，则D=2xy-2/2ab
C+D=1/2ab+2xy-2/2ab=2xy-1/2ab
综上所诉，所以C+D=2xy-1/2ab