(1)(2)
(1)解方程: (x+1)2-4=0 ;
(2)解不等式组: {-2x+3⩽1x-1<x3+1 .
解方程组: {3x-y=-4x-2y=-3 .
解方程组和不等式组:
(1) {x+y=02x-y=3 ;
(2) {3x+6>0x-2<-x .
计算: (x+2y)2+(x-2y)(x+2y)+x(x-4y).
化简: (aa-1+5a+9a2-1)÷a+3a-1.