99×87+102×98 有法用简便运算吗?(若有请写出来)谢啦
问题描述:
99×87+102×98 有法用简便运算吗?(若有请写出来)谢啦
答
原式=(100-1)X87+(100+2)x(100-2)=100x87-87+100x100-4=100x(87+100)-91=18700-91=18609
99×87+102×98 有法用简便运算吗?(若有请写出来)谢啦
原式=(100-1)X87+(100+2)x(100-2)=100x87-87+100x100-4=100x(87+100)-91=18700-91=18609