Question

已知关于x的方程1/2(1-x)=1+k的解与方程4/3(3x+2)=10/k-2/3(x-1)的解互为相反数求 K的值

Answer 1

1/2(1-x)=1+k

1-x=2（1+k）=2+2k

x=-2k-1

4/3(3x+2)=10k-2/3(x-1)

3x+2=3/4[10k-2/3(x-1)]

3x+2=15k/2-1/2(x-1)

6x+4=15k-(x-1)

7x=15k-3

x=15k/7-3/7

所以15k/7-3/7=-（-2k-1）=2k+1

15k-3=14k+7

k=10