当a=2,b=3时
a^2-2ab+b^2
=2^2-2*2*3+3^2
=4-12+9
=1
(a-b)^2
=(2-3)^2
=(-1)^2
=1
当a=5,b=-3
a^2-2ab+b^2
=5^2-2*5*(-3)+(-3)^2
=25+30+9
=64
(a-b)^2
=[5-(-3)]^2
=8^2
=64
3)根据(1)、(2)的计算结果,
a^2-2ab+b^2=(a-b)^2
99^2
=(100-1)^2
=100^2-2*100*1+1^2
=10000-200+1
=9801