Question

78x99十123的简便计算？

Answer 1

78*99+123=78*100+（123-78）=7800+45=7845

Answer 2

+78-78就变成了7800+123-78

Answer 3

简便运算
（78×99）＋123
＝7722＋123
＝7845

Answer 4

17×99+17＝17×99+17×1＝17×（99+1）＝17×100＝1700

Answer 5

17×99+17＝17×99+17×1＝17×（99+1）＝17×100＝1700