1) 6ах^2 - 12а^3х^3 = 6ах^2•( Х - 2ах )
2) с( а - b ) + b( b - a ) = ( a - b )•( c - b )
3) a( a - b)^2 - ( b - a)^3 = ( a - b)^2•( a + b - a ) = b•( a - b)^2
4) ac + bc - 2ad - 2bd = ( ac - 2ad ) + ( bc - 2bd ) = a( c - 2d ) + b( c - 2d ) = ( c - 2d )( a + b )