a, 5(x-y) - 5y(x-y) = 5( x-y )( 1-y )
b, 8x( x-z ) + 10x²( z-x ) = 2x( z-x )( 4+5x )
c, 27x²( y-1 ) - 9x³( 1-y ) = 27x²( y-1 ) + 9x³( y-1 )
= 9x²( y-1 )( 3+x )
d, 12x²y - 18xy² - 24x² = 6x( 2xy-3y²-4x )
e, 36 - ( 2-x )² = ( 6-2+x )( 6+2-x ) = ( 4+x )( 8-x )
g, ( 5x-9 )² - ( 7x+3 )² = ( 5x-9-7x-3 )( 5x-9+7x+3 )
= ( -2x-12 )( 12x-6 ) = -2( x+6 ). 6( 2x-1 ) = -12( x+6 )( 2x-1 )
h, 36 ( y-2 )² - 25 ( y+3 )² = [ 6( y-2 )]² - [ 5( y+3 )]²
= ( 6y-12-5y-15 )( 6y-12+5y+15 ) = ( y-27 )( 11y+3 )