化简 (1)6xy-10x2-5yx+7x2 (2)(3x2-2)-3(4x2-
题型:解答题
问题:
化简
(1)6xy-10x2-5yx+7x2
(2)(3x2-2)-3(4x2-2x-3)+2(2x2-1)
(3)先化简,再求值:3x2y-[2x2y-3(2xy-x2y)-xy],其中x=-1,y=-2.
化简
(1)6xy-10x2-5yx+7x2
(2)(3x2-2)-3(4x2-2x-3)+2(2x2-1)
(3)先化简,再求值:3x2y-[2x2y-3(2xy-x2y)-xy],其中x=-1,y=-2.