第2个回答 2019-12-23
设苹果价格为x元,橘子y元,瓜子z元
1.5x+3.5y+0.5z=16.3
(1)
2x+5y+0.5z=21.8
(2)
(1)×A
得:1.5Ax+3.5Ay+0.5Az=16.3A
(3)
(2)×B
得:2Bx+5By+0.5Bz=21.8B
(4)
(3)-(4)得:(1.5A-2B)x+(3.5A-5B)y+(0.5A-0.5B)z=16.3A-21.8B
令:
1.5A-2B=0.5
3.5A-5B=0.5
解得:A=3
B=2
16.3A-21.8B
=5.3
∴是多收了顾客的钱.