若方程组4x+3y=1,kx+(k-1)y=3的解x和y得和为2,求k的值

已知:4x+3y=1 ①kx+(k-1)y=3 ②x+y=2 ③由②-①式得:(k-4)x+(k-1-3)y=2 继续化简为:(k-4)(x+y)=2 ④把③代入④式得:(k-4)?2=2,算出k=5把k=5代入①②式得:4x+3y=1 ⑤5x+4y=3 ⑥由⑤?4-⑥?3得出x=-5把x=-5代入⑤式得y=...