Question

简便运算：3.6*31.4+43.9*6.4

Answer 1

3.6×31.4+43.9×6.4
=3.6×31.4+(31.4+12.5)×6.4
=3.6×31.4+31.4×6.4+12.5×6.4
=31.4×(3.6+6.4)+12.5×8×0.8
=31.4×10+100×0.8
=314+80
=394

Answer 2

3.6×31.4+43.9×6.4
=3.6×31.4+43.9×（10-.3.6）
=43.9×10-43.9×3.6+31.4×3.6
=439-3.6×（43.9-31.4）
=439-3.6×12.5
=439-45
=394
希望对你能有所帮助。