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3.6*31又2/5+43.9*6又2/5简便运算

题目详情
3.6*31又2/5+43.9*6又2/5简便运算
▼优质解答
答案和解析
3.6*31又2/5+43.9*6又2/5(化成小数)
=3.6×(6.4+25)+43.9×6.4
=3.6×6.4+43.9×6.4+3.6×25
=6.4×(3.6+43.9)+90
=6.4×47.5+90
=6.4×(50-2-0.5)+90
=6.4×50-6.4×2-6.4×0.5+90
=320-12.8-3.2+90
=410-(12.8+3.2)
=410-10-6
=394