(x+2)分之(x+1)-(x+7)分之1=(x+3)分之(x+2)-(x+6)分之1

问题描述:

(x+2)分之(x+1)-(x+7)分之1=(x+3)分之(x+2)-(x+6)分之1

(x+1)/(x+2)-1/(x+7)=(x+2)/(x+3)-1/(X+6)
(X+2-1)/(X+2)-1/(X+7)=(X+3-1)/(X+3)-1/(X+6)
1-1/(X+2)-1/(X+7)=1-1/(X+3)-1/(X+6)
1/(X+2)+1/(X+7)=1/(X+3)+1/(X+6)
1/(X+2)-1/(X+3)=1/(X+6))-1/(X+7)
1/(X+2)(X+3)=1/(X+6))(X+7)
(X+2)(X+3)=(X+6))(X+7)
X^2+5X+6=X^2+13X+42
解得X=-9/2