2/3u + 3v/4 =1/2 4/5u + 5v/6 =7/15

来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 12:19:46
2/3u + 3v/4 =1/2 4/5u + 5v/6 =7/15
x)37.UV0.7Q57R07 )ؚ$LΆh󞯝~,F?jXGt VaB#B C';ط鄞gӷ=9F0e sEepKaj0Ar&Fe`]&2[eF`'?m] "tR[]C=H>lz(l+ny>Ɏ]U: @$Y

2/3u + 3v/4 =1/2 4/5u + 5v/6 =7/15
2/3u + 3v/4 =1/2 4/5u + 5v/6 =7/15

2/3u + 3v/4 =1/2 4/5u + 5v/6 =7/15
答:
2/3u + 3v/4 =1/2…………(1)
4/5u + 5v/6 =7/15…………(2)
(1)两边同时乘以12、(2)两边同时乘以30得:
8u+9v=6………………(3)
24u+25v=14…………(4)
(1)*3-(2)得:
27v-25v=18-14
2v=4
解得:v=2
代入(3)得:8u+18=6
解得:u=-1.5
所以:方程组的解为u=-1.5,v=2