a) 6x2y28xy5=3x.2xy24y3.2xy2=3x4y36x2y28xy5=3x.2xy24y3.2xy2=3x4y3
b) 10xy2(x+y)15xy(x+y)3=2y.5xy(x+y)3(x+y)2.5xy(x+y)=2y3(x+y)210xy2(x+y)15xy(x+y)3=2y.5xy(x+y)3(x+y)2.5xy(x+y)=2y3(x+y)2
c) 2x2+2xx+1=2x(x+1)x+1=2x2x2+2xx+1=2x(x+1)x+1=2x
d) x2−xy−x+yx2+xy−x−y=x(x−y)−(x−y)x(x+y)−(x+y)=(x−y)(x−1)(x+y)(x−1)x2−xy−x+yx2+xy−x−y=x(x−y)−(x−y)x(x+y)−(x+y)=(x−y)(x−1)(x+y)(x−1)=x−yx+y