Question

用简便方法计算！要过程！

4800000/12.5/2.5/3
124.68+324.68+524.68+724.68+924.68

9.81×0.1+0.5×98.1+0.049×981
7.5 ×23+31 ×2.5
(4.8× 7.5 ×8.1 )/ (2.4 ×2.5 ×2.7)

Answer 1

用简便方法计算！要过程！
4800000/12.5/2.5/3
=4800000/3/12.5/2.5
=1600000/12.5/2.5
=1600000×8/（12.5×8）/2.5
=12800000/100/2.5
=128000/2.5
=128000×4/（2.5×4）
=512000/10
=51200

124.68+324.68+524.68+724.68+924.68
=（1+3+5+7+9）×100+24.68×5
=2500+121.36
=2621.36

9.81×0.1+0.5×98.1+0.049×981
=9.81×0.1+50×9.81+4.9×9.81
=9.81×（0.1+5+4.9）
=9.81×10
=98.1

7.5 ×23+31 ×2.5
=2.5×69+31×2.5
=2.5×（69+31）
=2.5×100
=250

(4.8× 7.5 ×8.1 )/ (2.4 ×2.5 ×2.7)
=（4.8/2.4）×（7.5/2.5）×（8.1/2.7）
=2×3×3
=18