巧解题 解方程组1/a+1/b=1,1/b+1/c=6,1/c+1/a=3
问题描述:
巧解题 解方程组1/a+1/b=1,1/b+1/c=6,1/c+1/a=3
答
1/a+1/b=1 1
1/b+1/c=6 2
1/c+1/a=3 3
1-2式=1/a-1/c=-5
3式 =1/c+1/a=3
两个式子相加得1/a+1/a=-2
a=-1带入1得b=1/2
代入3得c=1/4