六下脱式计算和解方程

Question

如题所述

Answer 1

(5/12-3/8)×72
=5/12×72-3/8×72
=30-27
=3

7/25×4/9+7/25×5/9
=7/25×(4/9+5/9)
=7/25×1
=7/25

6/7-5/24÷7/12
=6/7-5/24×12/7
=12/14-5/14
=7/14
=1/2

2/3-7/8+1/3
=(2/3+1/3)-7/8
=1-7/8
=1/8

5/6-(3/7-1/6)
=(5/6 1/6)-3/7
=1-3/7
=4/7

1-1/3-2/3
=1-(1/3+2/3)
=1-1
=0

1+3/5-1/10
=1+6/10-1/10
=1+1/2
=1又1/2

3/8-12/13+5/8
=3/8+5/8-12/13
=1-12/13
=1/13

1-(1/2-3/4)
=1 3/4-2/4
=1 1/4
=5/4

1-1/2-1/4
=1/2-1/4
=2/4-1/4
=1/4

2-1/4-3/4
=2-(1/4 3/4)
=2-1
=1

31.5×1.07-3.15×0.7
=3.15×10.7-3.15×0.7
=3.15×(10.7-0.7)
=3.15×10
=31.5

2.7×5.7-2.7 5.3×2.7
=2.7×(5.7-1 5.3)
=2.7×10
=27

0.625÷0.125×0.8
=(0.625×0.8)×8÷(0.125×8)
=0.5×8÷1
=4

18.6×6.1+ 3.9×18.6
=18.6×(6.1+ 3.9)
=18.6×10
=186

52.5x2.9 +5.25
=5.25x29+5.25
=5.25×(29+1)
=5.25×30
=157.5

0.72×1.25×2.5
=0.9×(0.8×1.25)×2.5
=0.9×1×2.5
=2.25

400.6x7-2003x0.4
=200.3x14-200.3x4
=200.3×（14-4）
=200.3×10
=2003

300÷125÷8
=300÷(125×8)
=300÷1000
=0.3

125x24
=125x8x3
=1000x3
=3000

25x99x4
=25x4x99
=100x99
=9900

250x32
=250x4x8
=1000x8
=8000

3/4÷5/8×3/10
=3/4×8/5×3/10
=9/5×1/5
=9/25

1/2-(4/5-1/2)
=1/2 1/2-4/5
=1-4/5
=1/5

4800÷25÷4
=4800÷(25x4)
=4800÷100
=4800÷100
=48

2/5-(3/8-3/5)
=2/5 3/5-3/8
=1-3/8
=5/8

3/4-(3/7-1/4)
=3/4 1/4-3/7
=1-3/7
=4/7

0.4×125×25×0.8
=(0.4×25)×(125×0.8)
=10×100
=1000

14.8×6.3-6.3×6.5+ 8.3×3.7
=(14.8-6.5)×6.3+ 8.3×3.7
=8.3×6.3 +8.3×3.7
=8.3×(6.3 +307)
=8.3×10
=83

933-157-43
=933-(157+43)
=933-200
=733

32×125×25
=4×8×125×25
=(4×25)×(8×125)
=100×1000
=100000

1.8 18÷1.5-0.5×0.3
=1.8 12-0.15
=13.8-0.15
=13.65

6.5×8 +3.5×8-47
=52 +28-47
=80-47

1/2-(4/5-1/2)
=1/2 1/2-4/5
=1-4/5
=1/5

4800÷25÷4
=4800÷(25x4)
=4800÷100
=4800÷100
=48

2/5-(3/8-3/5)
=2/5 3/5-3/8
=1-3/8
=5/8

3/4-(3/7-1/4)
=3/4 1/4-3/7
=1-3/7
=4/7

1/3x-1/4x=12
解：4/12x-3/12x=12
1/12x=12
x=12*12
x=144

1/2x 1/3x=5/6
解：(1/2x 1/3x)×6=5/6×6
3x 2x=5
5x=5
x=5÷5
x=1

2x/3 5x/7=23/42
解：(2x/3 5x/7)×42=23/42×42
28x 30x=23
58x=23
x=23/58

5/6-x=1/4
解：x=5/6-1/4
x=10/12-3/12
x=7/12

x÷4/5=2/7
解：x=2/7×4/5
x=8/35

14 5x=42
解：5x=42-14
5x=28
x=28/5
x=5。
6

7×5 65x=100
解：35 65x=100
65x=100-35
x=65/65
x=1

4x-8*7=28
解：4x=28 56
x=84/4
x=21