- 解下列方程组(二元一次方程)(1)3(x
- (1) 3(x-1)=y+5
5(y-1)=3(x+5)
(2) (2u/3)+(3v/4)=1/2
(4u/5)+(5v/6)=7/15
过程要详细啊
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(1) 3(x-1)=y+5 — 3x-3=y+5 = y=3x-8.........①
5(y-1)=3(x+5) = 5y-5=3x+15 = 5y=3x+20........②
①代人② 得: 15x-40=3x+20
所以 x=15 y=37
(2) (2u/3)+(3v/4)=1/2 -----① ①*12得 8u+9v=6---③
(4u/5)+(5v/6)=7/15 -------② ②*30得 24u+25v=14 ---④
③*3-④得 2v=4---v=2---⑤ 代入③式 8u=-12---u=-3/2