问题
解答题
化简下列各题:
(1)2a2-3a+1-a2+6a-7
(2)(5x2-3xy+y2)-2(x2-xy+y2)
答案
(1)原式=a2+3a-6;
(2)原式=5x2-3xy+y2-2x2+2xy-2y2
=3x2-xy-y2.
化简下列各题:
(1)2a2-3a+1-a2+6a-7
(2)(5x2-3xy+y2)-2(x2-xy+y2)
(1)原式=a2+3a-6;
(2)原式=5x2-3xy+y2-2x2+2xy-2y2
=3x2-xy-y2.