若x、y、z满足2x+3y+z=18,4x-3y+5y=24,求x+3y的值._数学解答

若x、y、z满足2x+3y+z=18,4x-3y+5y=24,求x+3y的值.

人气：438 ℃　时间：2020-03-26 11:24:13

解答

2x+3y+z=18 (1)
4x-3y+5y=24 (2)
(1)*5-(2)
10x+15y+5z-4x+3y-5z=90-24
6x+18y=66
x+3y=11