1.a^2-b^2
2.(a+b)(a-b)
3.a^2-b^2 = (a+b)(a-b)
4.(1-1/2)(1+1/2)(1-1/3)(1+1/3).(1-1/100)(1+1/100)=1/2 * 3/2.101/100 * 99/100
=1/2 * 101/100=101/200
1.a^2-b^2
2.(a+b)(a-b)
3.a^2-b^2 = (a+b)(a-b)
4.(1-1/2)(1+1/2)(1-1/3)(1+1/3).(1-1/100)(1+1/100)=1/2 * 3/2.101/100 * 99/100
=1/2 * 101/100=101/200