第1个回答 2011-05-24
(-4m^2+n^2)÷(2m+n)
= (2m-n)(2m+n)÷(2m+n)
=2m-n
(x^2-4x+4)÷(1-1/2x)
=(x-2)^2÷((2-x)/2)
=(2-x)^2÷((2-x)/2)
=2(2-x)
(1-81x^4)÷(1+3x)÷(1+9x^2)
=(1-3x)(1+3x)(1+9x^2)÷(1+3x)÷(1+9x^2)
=1-3x
(2x-1)(x+3)=0
x1=1/2 x2=-3
2x^2+3x=0 x(2x+3)=0
x1=0 x2=-3/2
(x+5)^2=1
x1+5=1 x2+5=-1
x1=-4 x2=-6
(2x+1)^2=(1-x)^2
(2x+1)^2-(1-x)^2=0
(x+2)(3x)=0
x1=-2 x2=0
0.2x^2+5x=0
x^2+25x=0
x(x+25)=0
x1=0 x2=-25
(2-x)^2=4(x+3)^2
4(x+3)^2-(2-x)^2=0
(2x+6+2-x)(2x+6-2+x)=0
(x+8)(3x+4)=0
x1=-8 x2=-4/3