a) 5x2 - 5xy - 3x + 3y
= 5x.(x - y) - 3.(x - y)
= (x - y).(5x - 3)
b) x3 - 2x2 - x + 2
= x2.(x - 2) - (x - 2)
= (x - 2).(x2 - 1)
= (x - 2).(x - 1).(x + 1)
a/ 5x2-5xy-3x+3y
=5x.(x-y)-3(x-y)
=(5x-3).(x-y)
b/ x3-2x2-x+2
=x2.(x-2)-(x-2)
=(x2-1).(x-2)
=(x-1).(x+1).(x-2)