（1）两边同乘以6（y-2）,得
2(3y+5)=3(y-2)+3(5y-4)
6y+10=18y-18
12y=28
y=7/3
(2) 通分：3/((x+4)(x+7))=3/((x+3)(x+6))
(x+4)(x+7)=(x+3)(x+6)
11x+28=9x+18
2x= -10
x= -5