全部简便算:①(38.7-18.6÷3.1)×0.8 ②7.09×10.8-8×0.709 ③15.6×13.1-15.6-15.6×2.1 ④20÷1.25÷8
问题描述:
全部简便算:①(38.7-18.6÷3.1)×0.8 ②7.09×10.8-8×0.709 ③15.6×13.1-15.6-15.6×2.1 ④20÷1.25÷8
答
全部简便算:①(38.7-18.6÷3.1)×0.8 ②7.09×10.8-8×0.709 ③15.6×13.1-15.6-15.6×2.1 ④20÷1.25÷8