1) a ( x + y + z )
2) x^2 ( x^2 + x - 1)
3) -x ( a + b + c)
4) ( a + b )( x^2 + y^2 )
5) ( x - y )( a^2 - ab + b^2 )
6) x ( a + b ) + y ( a + b ) = ( x + y )( a + b )
7) x ( a + b ) - y ( a + b ) = ( x - y )( a + b )
8) 12 ( n^3 - 1 ) + n ( n - 1 ) = 12 ( n - 1 )( n^2 + n + 1) + n ( n - 1 ) = ( n - 1 )( 12n^2 + 13n + 12 )
9) c ( a + 3 ) + 4 ( a + 3 ) = (a + 3 )( c + 4 )
10) 6p (a + 3 ) - 6 ( a + 3 ) = (6p - 6 )( a + 3 )