49×42 49 49×57怎么用简便运算?

2025-03-17 16:45:50
推荐回答(2个)
回答1:

运用乘法分配律使计算简便:
49×42+49+49×57
=49×(42+1+57)
=49×100
=4900

回答2:

49×42+49+49×57
=49×(42+1+57)
=49×100
=4900