Question

计算：3.68×15.7-31.4+15.7×0.32=________．

Answer 1

31.4
分析：首先3.68×15.7+15.7×0.32通过因式分解提取公因数15.7，使3.68+0.32结果为整数4．再-31.4计算．
解答：3.68×15.7-31.4+15.7×0.32
=15.7×（3.68+0.32）-31.4
=15.7×4-31.4
=31.4×2-31.4
=31.4
故答案为31.4
点评：本题考查因式分解的应用．解决本题通过因式分解提取公因数15.7，从而使3.68+0.32结果为整数4，大大降低了计算的数据量．