Question

能简计算就简算（1）4.2x2.4+5.8x2.4（2）8.1/0.25（3）（40-8.8）x12.5/2.5 （4）1.8/[(7.32+1.68)/2.5]

(5)8.75x(5.76+4.2-5.76)(6)0.2/[(1+1.8)x0.5]

Answer 1

（1）4.2x2.4+5.8x2.4
=（4.2+5.8）×2.4
=10×2.4
=24
（2）8.1/0.25
=8.1×4/（0.25×4）
=32.4
（3）（40-8.8）x12.5/2.5
=（40-8.8）×5
=40×5-8.8×5
=200-44
=156
（4）1.8/[(7.32+1.68)/2.5]
=1.8/[9/2.5]
=1.8/9×2.5
=0.2×2.5
=0.5
(5)8.75x(5.76+4.2-5.76)
=8.75×4.2
=36.75
(6)0.2/[(1+1.8)x0.5]
=0.2/[2.8x0.5]
=0.2/1.4
=1/7

Answer 2

（3）（40-8.8）x12.5/2.5 =（5-1.1）×8x12.5/2.5 =3.9x100/2.5 =3.9X40 =156 其他同下面的