` \color{#0074D9}{#n}\color{#0088DD}{q}\color{#3399FF}{o}\color{#66AAFF}{c}\color{#99CCFF}{c} `

`a) x^2 - 3x + xy - 3y `

`= (x^2 - 3x) + (xy - 3y) `

` = x(x-3) + y(x-3) `

` = (x+y)(x-3) `

`b) x^2 - xy + x - y `

` = (x^2 - xy) + (x-y) `

` = x(x - y) + 1(x-y) `

` = (x+1)(x-y) `

`c) 3x^2 -3xy - 5x + 5y `

` = (3x^2 - 3xy) + (-5x + 5y) `

` = 3x(x-y) - 5(x-y) `

` = (3x - 5)(x-y) `

`d) x^2 - 2x + x - 2 `

` = x(x-2) + (x-2) `

` = (x+1)(x-2) `