初一数学计算题求助~高手进~

1.用简便计算:
(1)49.9^2 +9.98+0.1^2
=(49.9+0.1)^2
=50^2
=2500

(2)9999^2 +19999
=9999^2+19998+1
=(9999+1)^2
=10000^2
=100000000

就是用完全平方公式做的。
(a+b)^2=a^2+2ab+b^2
(a-b)^2=a^2-2ab+b^2

1、(50-0.1)^2+9.98+0.1^2
=2500-10+0.01+9.98+0.01
=2500
2、9999^2+10000+9999
=9999(9999+1)+10000
=10000(9999+1)
=100000000

太简单的题目拉