Question

若方程组4x+3y=5,kx-(k-1)y=8的解中的x值比y的值的相反数大1,求k的值.

Answer 1

X的值比Y的值的相反数大1

则X=-Y+1

X+Y=1.(1)

又4X+3Y=5.(2)

(1)*4-(2),得

Y=-1

代入(1)中,

X-1=1

X=2

把X=2,Y=-1代入KX-(K-1)Y=8中

K*2-(K-1)*(-1)=8

2K+K-1=8

3K=9

K=3