(1)原式=﹣
×3×
×﹣
=
;
(2)原式=
×(﹣9×
﹣
)×(﹣
)
=
×(﹣
)×(﹣
)
=
;
(3)原式=(﹣12x+10x)+(6y﹣y)+(﹣3﹣2)
=﹣2x+5y﹣5;
(4)原式=2x﹣3y+7+6x﹣5y﹣2
=(2x+6x)+(﹣3y﹣5y)+(7﹣2)
=8x﹣8y+5.
(1)原式=﹣
×3×
×﹣
=
;
(2)原式=
×(﹣9×
﹣
)×(﹣
)
=
×(﹣
)×(﹣
)
=
;
(3)原式=(﹣12x+10x)+(6y﹣y)+(﹣3﹣2)
=﹣2x+5y﹣5;
(4)原式=2x﹣3y+7+6x﹣5y﹣2
=(2x+6x)+(﹣3y﹣5y)+(7﹣2)
=8x﹣8y+5.