TÌM X BIẾT

TÌM X BIẾT:
a) ( x-1 ).( x^2+x+1 ) - x( x+2 )( x-2 ) = 5
b) ( x+1 )^3 - ( x-1 )^3 - 6( x-1 )^2 = -10
c) ( x-3 )( x^2+3x+9 ) + x( x+2 )( 2-x ) =1
d) ( x-1 )^3 - ( x-3 )( x^2-3x+9 ) + 3( x^2 -4 ) =2