84÷63X3 1X5.3+2.1X6.2-2.1X1.5
问题描述：
84÷63X3 1X5.3+2.1X6.2-2.1X1.5
答
﹙1﹚84÷63×3
＝21×4÷21÷3×3
＝4×﹙21÷21﹚×﹙3÷3﹚
＝4
﹙2﹚1×5.3＋2.1×6.2－2.1×1.5
＝5.3＋2.1×﹙6.2－1.5﹚
＝5.3＋2.1×4.7
＝5.3＋4.7＋1.1×4.7
＝10＋5.17
＝15.17.