Q1,
`3x-3y-x^2+2xy-y^2`
`=3(x-y) - (x-y)^2`
`=(x-y)(3-x+y)`
Q2,
`x^2 - 2xy+y^2 - xz+yz`
`=(x-y)^2 -z(x-y)`
`=(x-y)(x-y-z)`
R,
`x^2-2x-y^2+1`
`=(x-1)^2-y^2`
`=(x-y-1)(x+y-1)`
S,
`9x^2-a^2-2ab-b^2`
`=9c^2-(a+b)^2`
`=(3c-a-b)(3c+a+b)`
T,
`x^3-2x^2y+xy^2-9x`
`=x(x^2-2xy+y^2-9)`
`=x[(x-y)^2-9]`
`=x(x-y-9)(x-y+9)`
U,
`-3x^2+6xy+12z^2-3y^2`
`=-3(x^2-2xy+y^2 - 4z^2)`
`=-3[(x-y)^2-4z^2]`
`=-3(x-y-2z)(x-y+2z)`
V,
`a^3 + 3a^2 + 3a +1 - 27b^3`
`=(a+1)^3 - 27b^3`
`=(a-3b+1)[(a+1)^2 + 3b(a+1) + 9b^2]`
`=(a-3b+1)(a^2+2a+1+3ab+3b+9b^2)`
~~~~~~~~~~~~GOOD LUCK~~~~~~~~~
