2.
a) (x-3)²-x(x-5)=x²-6x+9-x²+5x=9-x
b)(x+4)²-x(x+7)=x²+8x+16-x²-7x=x+16
c)(x+4)²+(x-5)²=x²+8x+16+x²-10x+25=2x²-2x+41
d)(x+2)²-(x-3)²=x²+4x+4-x²+6x-9=10x-5=5(2x-1)
e)(2x+3)²-4(x+1)(x-1)=4x²+12x+9-4(x²-1)=4x²+12x+9-4x²+4=12x+13
f)(3x-1)²-9(x-2)(x+2)=9x²-6x+1-9(x²-4)=9x²-6x+1-9x²+36=37-6x
