Question

用简便方法计算:负八加负七点二乘以负二点五乘以十二分之五等于?简便运算……非常感谢

Answer 1

=-8+7.2×2.5×12分之5

= -8+（12×0.6）×2.5×12分之5

= -8+（12×12分之5）×0.6×2.5

= -8+5×0.6×2.5

= -8+3×2.5

= -8+7.5

= -0.5