Question

请教几道小学六年级数学题

呃…写出步骤
77x(9/55-9/77)
0.4x(3.2-0.8)÷1.2
(7/8-5/16)x(5/9+2/3)
3.6÷1.2+0.5x5
4/5x2/3+1/5÷3/4

Answer 1

77x(9/55-9/77)
=77x9/55-77x9/77
=7x9/5-9
=9x7/5-9
=9x(7/5-1)
=9x2/5
=18/5
0.4x(3.2-0.8)÷1.2
=0.4x2.4÷1.2
=0.4x2x1.2÷1.2
=0.8
(7/8-5/16)x(5/9+2/3)
=﹙14/16-5/16﹚×﹙5/9＋6/9﹚
=9/16×11/9
=11/16
3.6÷1.2+0.5x5
=3＋2.5
=5.5
4/5x2/3+1/5÷3/4
=8/15＋1/5x4/3
=8/15＋4/15
=12/15
=4/5

追问

1/5÷[(2/3÷1/5)x1/3]
这个

追答

1/5÷[(2/3÷1/5)x1/3]
=1/5÷[2/3×5×1/3]
=1/5÷10/9
=1/5×9/10
=9/50
1/2+1/3÷2/3
=1/2＋1/3×3/2
=1/2＋1/2
=1

Answer 2

解：1，77x(9/55-9/77)=7x（9/5-9/7）=7x9x2/35=18/5。
2，0.4x(3.2-0.8)÷1.2=0.4x2.4/1.2=0.4x2=0.8.
3，(7/8-5/16)x(5/9+2/3)=9/16x11/9=11/16.
4，3.6÷1.2+0.5x5=3+2.5=5.5.
5，4/5x2/3+1/5÷3/4=8/15+4/15=12/15=4/5.

追问

额再问个问题
1/5÷[(2/3÷1/5)x1/3]
1/2+1/3÷2/3

Answer 3

77x(9/55-9/77)=7*9/5-9=12.6-9=3.6
0.4x(3.2-0.8)÷1.2=0.4*2.4÷1.2=0.4
(7/8-5/16)x(5/9+2/3)=(14/16-5/16)(5/9+6/9)=(9/16)(11/9)=11/16
3.6÷1.2+0.5x5=3+2.5=5.5
4/5x2/3+1/5÷3/4=8/15+4/15=12/15=4/5

Answer 4

77x(9/55-9/77)=77x(1/5-1/7)x9/11=7x9x(7/35-5/35)=7x9x2/35=18/5
0.4x(3.2-0.8)÷1.2=0.4x2.4/1.2=0.4x2=0.8
(7/8-5/16)x(5/9+2/3)=(14/16-5/16)x(5/9+6/9)=(9/16)x(11/9)=11/16
3.6÷1.2+0.5x5=3+2,5=5.5
4/5x2/3+1/5÷3/4=8/15+4/15=12/15=4/5

Answer 5

1，
77 × (9/55-9/77)
= 77 × 9/55-77 × 9/77
= 7 × 9/5-9
= 9 × 7/5-9
= 9 × (7/5-1)
= 9 × 2/5
= 18/5

2，
0.4 × (3.2-0.8)÷1.2
= 0.4 × 2.4÷1.2
= 0.4 × 2 × 1.2÷1.2
= 0.8

3，
(7/8-5/16) × (5/9+2/3)
=(14/16-5/16﹚ × ﹙5/9 + 6/9﹚
= 9/16 × 11/9
= 11/16

4，
3.6÷1.2+0.5 × 5
= 3 + 2.5
= 5.5

5，
4/5 × 2/3+1/5÷3/4
= 8/15 + 1/5 × 4/3
= 8/15 + 4/15
= 12/15
= 4/5