答案
解:(1)原式=1+4-1=4;
(2)原式=4x
6y
2·(-2)xy+(-8)x
9y
3÷2x
2=-8x
gy
3-4x
gy
3=-12x
gy
3;
(3)原式=6m
2n÷(-3m
2)-6m
2n
2÷(-3m
2)-3m
2÷9-3m
2)=-2n+2n
2+1;
(4)原式=(2x-3)(2x-3-2x-3)=(2x-3)×(-6)=-12x+18.
解:(1)原式=1+4-1=4;
(2)原式=4x
6y
2·(-2)xy+(-8)x
9y
3÷2x
2=-8x
gy
3-4x
gy
3=-12x
gy
3;
(3)原式=6m
2n÷(-3m
2)-6m
2n
2÷(-3m
2)-3m
2÷9-3m
2)=-2n+2n
2+1;
(4)原式=(2x-3)(2x-3-2x-3)=(2x-3)×(-6)=-12x+18.