30/x+10 + 30/x-6 = 60/x

`30/(x+10) + 30/(x-6)=60/x  (đkxđ: x ne 0 , x ne -10 , x ne 6)`

`=>(30x(x-6))/(x(x-6)(x+10)) +(30x(x+10))/(x(x-6)(x+10)) =(60(x-6)(x+10))/(x(x-6)(x+10))`

`=>30x(x-6)+30x(x+10)=60(x-6)(x+10)`

`=>x(x-6)+x(x+10)=2(x-6)(x+10)`

`=>x^2 -6x+x^2 +10x=2(x^2 +10x-6x-60)`

`=>2x^2 +4x=2x^2 +20x-12x-120`

`=>4x=8x-120`

`=>-4x=-120`

`=>x=30 (TM)`
Vậy `x=30`