Question

已知方程组 7x-3y=0 2x-y=-1 的解是方程3x+ky=44的解,求k的值

Answer 1

7x-3y=0 (1)2x-y=-1 (2)由(2)得:-y=-1-2xy=1+2x (3)(3)代入(1):7x - 3(1+2x)=07x - 3 -6x =0x- 3 =0x = 3x=3代入(3)y=1+2*3y =1+6y = 7x=3 ,y=7 代入 3x+ky=443*3+ 7k=449+7k=447k =44-97k=35k=5