nlineee
花朵
共回答了15个问题采纳率:100% 举报
1)
(x+2)/(x+1)=[(x+1)+1]/(x+1)=(x+1)/(x+1)+1/(x+1)=1+1/(x+1)
同理:(x+4)/(x+3)=1+1/(x+3)
(x+6)/(x+5)=1+1/(x+5)
(x+8)/(x+7)=1+1/(x+7)
∴原方程可化为:
1/(x+1)-1/(x+3)=1/(x+5)-1/(x+7)
2/(x+1)(x+3)=2/(x+5)(x+7)
x²+4x+3=x²+12x+35
x=-4
经检验,x=-4是原方程的解.
2)
移项:1/(x+5)-1/(x+6)=1/(x+7)-1/(x+8)
1/(x+5)(x+6)=1/(x+7)(x+8)
(x+5)(x+6)=(x+7)(x+8)
x²+11x+30=x²+15x+56
x=-13/2
经检验,x=-13/2是原方程组的解.
1年前
6