计算 (1)(x-y)(x+3) (2)(5a2+8a)+(3a2-7a+5)
问题:
计算
(1)(x-y)(x+3)
(2)(5a2+8a)+(3a2-7a+5)
(3)(-3)5•(-3)2
(4)x2y2(-x2y)
(5)(2a+3b)(a-b)
(6)(5a3-2a+a2)÷(-2a)
计算
(1)(x-y)(x+3)
(2)(5a2+8a)+(3a2-7a+5)
(3)(-3)5•(-3)2
(4)x2y2(-x2y)
(5)(2a+3b)(a-b)
(6)(5a3-2a+a2)÷(-2a)