-3x(a-2b)y(7)与2x(8)y(5a+b)是同类项,则有:a-2b=87=5a+b14=10a+2b=10a+(a-8)a=2b=7-5a=-3
-3x(a-2b)y(7)与2x(8)y(5a+b)是同类项a-2b=85a+b=7 b=7-5a=-3