199+99X99用简便方法算,该怎么算?
199+99X99=1+99+99+99x99=100+99(1+99)=100+99x100=100+9900=10000
解:简便计算方法如下
199+99×99
=100+99+99×99
=100+99×(1+99)
=100+99×100
=100+9900
=10000
原式=100+99+99*99=100+99*(1+99)=100+9900=10000
原式=100+99+99*99
=100+99*(1+99)
=100+99*100
=100*(1+99)
=100*100
=10000
乘法分配律为:两个数的和与一个数相乘,先将它们与这个数分别相乘,再相加,积不变.即:(a+b)×c=a×c+b×c.反过来则:a×c+b×c=(a+b)×c
199+99×99
= 99+100+99× 99
= 99× ( 1+99)+100
= 99×100+100
= 100× ( 99+1)
= 100× 100
= 10,000