Đáp án + Giải thích các bước giải:
`a)` `S=(x/(x^2-36)-(x-6)/(x^2+6x)):(2x-6)/(x^2+6x)+x/(6-x)(xnepm6,xne0)`
`=(x/[(x-6)(x+6)]-(x-6)/[x(x+6)]):(2x-6)/[x(x+6)]+x/(6-x)`
`=((x*x)/[x(x-6)(x+6)]-[(x-6)(x-6)]/[x(x-6)(x+6)])*[x(x+6)]/(2x-6)+x/(6-x)`
`=(x^2-(x^2-12x+36))/[x(x-6)(x+6)]*[x(x+6)]/[2(x-3)]+x/(6-x)`
`=(x^2-x^2+12x-36)/[x(x-6)(x+6)]*[x(x+6)]/[2(x-3)]+x/(6-x)`
`=[12(x-3)]/[x(x-6)(x+6)]*[x(x+6)]/[2(x-3)]+x/(6-x)`
`=[12x(x-3)(x+6)]/[2x(x-6)(x+6)(x-3)]+x/(6-x)`
`=6/(x-6) + x/(6-x)`
`=6/(x-6)-x/(x-6)`
`=(6-x)/(x-6)`
`=[-(x-6)]/(x-6)=-1`
`b)` Xem lại đề :v
