题目内容：

4.2×1.2-5.2×0.7的简便运算

优质解答

4.2×1.2-5.2×0.7 =0.7×6×1.2-5.2×0.7 =0.7×7.2-5.2×0.7 =0.7×(7.2-5.2) =0.7×2 =1.4