Question

79×42+79+79+57，简便方法怎么做？

Answer 1

79×42+79+79+57
=79×（42+1+1）+57
=79×44+57
=（80-1）×44+57
=80×44-1×44+57
=3520-44+57
=3520+（57-44）
=3520+13
=3533
怀疑题目出错，貌似应该是
79×42+79+79×57
=79×（42+1+57）
=79×100
=7900

Answer 2

79×42+79+79+57，简便计算？
解：原式=79×42+79×1+79×1+57
=79×（42+1+1）+57
=79×（40+4）+57
=79×40+79×4+57
=3160+316+57
=3476+57
=3433

追答

最后=3533

Answer 3

44个79加57，也就是加上44再加13，相当于44个80再加上13，即原式=79x44+44+13=80x44+13=3520+13=3533。

Answer 4

回答：
79X42十(79X2十57)

=3318十215

=3533

Answer 5

79×42+79+79+57
=79×(42+1+1)+57
=79×44+44+13
=44×(79+1)+13
=3533.