化简x-y分之x^2+y-x分之y^2
=(x^2-y^2)/(x-y)
=(x+y)(x-y)/(x-y)
=x+y
(x-2分之x+x+2分之x)÷x^2-4分之4x
=2x^2/(x^2-4)÷4x/(x^2-4)
=x/2
解不等式组2x-1<0,2分之1(x+4)<3
2x<1, x+4<6
x<1/2, x<2
解集为 x<1/2
分解因式x^2(x-y)+(y-x)
=(x-y)(x^2-1)
=(x-y)(x+1)(x-1)
(a^2+4)^2-16a^2
=(a^2+4-4a)(a^2+4+4a)
=(a-2)^2(a+2)^2
ax^2-4ax+4a
=a(x^2-4x+4)
=a(x-2)^2
2x-1<0
解:2x<1
x<0.5
2分之1(x+4)<3
解:x+4<6
x<2