方程组求解:1:3x+y=2 25x-2y=0 2:4x-3y=14 5x+3y=31

问题描述:

方程组求解:1:3x+y=2 25x-2y=0 2:4x-3y=14 5x+3y=31

3x+y=2 (1)
25x-2y=0(2)
(1)*2
6x+2y=4(3)
(2)+(3)
31x=4
x=4/31
y=2-3x=2-12/31=50/31
4x-3y=14 (1)
5x+3y=31(2)
(1)+(2)
9x=45
x=5
代入(1)
20-3y=14
3y=6
y=2
x=5
y=2