Question

49x78十78用乘法分配律进行简便计算(递等式？

Answer 1

简便计算如下，提取公因式49，所以原式=（49+1）×78=50×78=50×（80-2）=50×80-50×2=4000-100=3900

Answer 2

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
49×78+78
= 78× ( 49+1)
= 78×50
= 3900

Answer 3

49x78十78用简便计算：
49x78十78=78×(49+1)
=78×50
=3900

Answer 4

49x78+78
=78x(49+1)
=78x50=3900

Answer 5

49×78+78
=78×（49+1）
=78×50
=39×2×50
=39×100
=3900