3[1/x+1/(x+6)]+(x-3)/(x+6)=1
3/x+3/(x+6)]+(x-3)/(x+6)=1
3/x+(3+x-3)/(x+6)=1
3/x+x/(x+6)=1
3(x+6)+x²=x(x+6)
3x+18+x²=x²+6x
18=3x
x=6
3[1/x+1/(x+6)]+(x-3)/(x+6)=1
3/x+3/(x+6)]+(x-3)/(x+6)=1
3/x+(3+x-3)/(x+6)=1
3/x+x/(x+6)=1
3(x+6)+x²=x(x+6)
3x+18+x²=x²+6x
18=3x
x=6