X+3分之5X-X-3分之9等于5
问题描述：
X+3分之5X-X-3分之9等于5
答
5X/(X+3)-9/(X-3)=5
( 5X*(X-3)-9*(X+3) )/( (X+3)*(X-3) )=5
5X*(X-3)-9*(X+3)=5*( (X+3)*(X-3) )
5X*X-15X-9X-27=5X*X-45
24X+27=45
24X=18
X=0.75