Question

301×89-89用简便计算

Answer 1

301X89-89
=301X89-1X89
=【301-1】X89
=27600

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
301×89-89
= （301-1）×89
= 300×89
= 26700