(1) -(x-1)(x+1)-(3-x)(-3-x)
=(1-x)(1+x)+(3-x)(3+x)
=1-x²+9-x²
=10-2x²
(2)(3x+4)(3x-4)+(-2x-3)(3x-2)
=9x²-16+(-6x²+4x-9x+6)
=3x²-5x-10