x.y满足方程组(3ax+4y=9 (6ax+5y=27,那么3ax+y的值是?

问题描述:

x.y满足方程组(3ax+4y=9 (6ax+5y=27,那么3ax+y的值是?

因为3ax+4y=9
所以6ax+8y=18
又6ax+5y=27
所以3y=-9
所以y=-3
故ax=7
故3ax+y=18