Question

三十九点七乘二点八加三点九七乘七十二怎样简便计算

Answer 1

三十九点七乘二点八加三点九七乘七十二怎样简便计算

39.7×2.8+3.97×72
=39.7×2.8+39.7×7.2
=39.7×（2.8+7.2）
=39.7×10
=397

三点九加三十九点九加三百九十九点九加三千九百九十点九点九.用简便方法计算

3.9+39.9+399.3+3999.9
=4+40+400+4000-0.1×4
=4444-0.4
=4443.6

十九点九四加九十九点七乘以九十九点八怎样简便运算

（20-0.06）+（100-0.03）*（100-0.02）
=20-0.06+10000-20-30+0.06
=9970

三十九点五乘十点二减3.95乘二的简便运算

39.5×10.2-3.95×2
=39.5×10.2-39.5×0.2
=39.5×(10.2-0.2)
=39.5×10
=395

十九点七乘101减十九点七乘零点一的简便演算法.

19.7x101-19.7x0.1
=19.7x(101-0.1)
=19.7x100.9
=1987.73

九点七乘以九十九点八怎样简便运算

9.7×99.8
=9.7×(100-0.2)
=9.7×100-9.7×0.2
=970-1.94
=968.06

十二点七点减九点九的简便计算

十二点七点减九点九的简便计算
12.7-9.9
=12.7-(10-0.1)
=12.7-10+0.1
=2.7+0.1
=2.8.

七十二乘零点零三加零点三乘二点八简便计算

72×0.03﹢0.3×2.8
=7.2×0.3+0.3×2.8
=0.3×﹙7.2+2.8﹚
=0.3×10
=3

三点五x减去二点七x等于三十九点六解方程

3.5x-2.7x=39.6
0.8x=39.6
x=39.6÷0.8
x=49.5