`a)` `(x+3)(x^2-3x+9)-x^2(x-2)=2x^2-5`

`=>x^3+27-x^3+2x^2-2x^2+5=0`

`=>0=-32` (Vô lý)

Vậy không có `x` thỏa mãn.$\\$

`b)` `5x-3{4x-3[4x-3(5x-2)]}=182`

`=>5x-3[4x-3(4x-15x+6)]=182`

`=>5x-[4x-3(6-11x)]=182`

`=>5x-(4x-18+33x)=182`

`=>5x-(37x-18)=182`

`=>5x-37x+18=182`

`=>-32x=164`

`=>x=-41/8`

Vậy `x=-41/8`$\\$

`c)` `(3x+2)(2x+9)-(x+2)(6x+1)=(x+1)-(x-6)`

`=>6x^2+31x+18-6x^2-13x-2=x+1-x+6`

`=>18x=-9`

`=>x=-1/2`

Vậy `x=-1/2`