五分之四乘三加五分之二乘七加五分之一乘四用简便方法做
问题描述:
五分之四乘三加五分之二乘七加五分之一乘四用简便方法做
答
4/5x3+2/5x7+1/5x4
=1/5x12+1/5x14+1/5x4
=1/5x(12+14+4)
=1/5x30
=6