Cevap:
Zor okunuyor
3) (2x-3-(2x-1))(2x-3+(2x-1))
=-2*(4x-4)=-8x+8
4) a) (2008-2007)(2008+2007)=4015
b) (115-112)(115+112)=3*(227)=681
c) (90-80)(90+80)=10*170=1700