Question

3.52x0.79-0.173x7.9+1.79x0.21简便运算

Answer 1

解:将7.9运用乘法分配律化为0.79ⅹ10同0.173连乘，将1.79x0.21运用拆分法化为1x0.21+0.79x0.21，提取0.79，然后按四则运算法则进行计算。计算过程
3.52ⅹ0.79-0.173x7.9+1.79ⅹ0.21
=3.52x0.79-0.173ⅹ10x0.79+1ⅹ0.21+0.79x0.21
=0.79ⅹ(3.52-1.73+0.21)
+0.21
=0.79x2+0.21
=1.58+0.21
=1.79。

Answer 2

3.52x0.79-0.173x7.9+1.79x0.21
=3.52x0.79-1.73x0.79+0.79x0.21+0.21
=(3.52 -1.73+0.21)x0.79+0.21
=2x0.79+0.21
=1.79