简便运算:9999²+19999
问题描述:
简便运算:9999²+19999
答
9999²+19999
=(10000-1)²+19999
=100000000-20000+1+19999
=99980000+(1+19999)
=99980000+20000
=100000000
答
9999²+19999
=9999²+2×9999 +1
=(9999+1)²
=10000²
=100000000