Question

用加减消元法解下列方程组：{x+2y=-1,3x-2y=11 {3x-2y=2,5x+4y=1 {2x-3y=5,3x-

Answer 1

x+2y=-1 (1)

3x-2y=11 (2)

(1)+(2)得

4x=10

x=5/2x=2.5代入(1)得

2.5+2y=-1

y=-7/4

3x-2y=2 (1)

5x+4y=1 (2)

(1)*2+(2)得

x=5/11

代入(2)得

y=-7/22