8 + 45 + 7 + 1 = ?
Tính nhanh
a) 31/23 - (7/32 + 8/23)
b) 38/45 - (8/45 - 17/51 - 3/11)
c)(1/3 + 12/67 + 13/41) - ( 79/67 - 28/41)
d) 1/5 + -1/6 + 1/7 + -1/8 + 1/9 + 1/8 + -1/7 + 1/6 + -1/5
Tính nhanh
a) 31/23 - (7/32 + 8/23)
b) 38/45 - (8/45 - 17/51 - 3/11)
c)(1/3 + 12/67 + 13/41) - ( 79/67 - 28/41)
d) 1/5 + -1/6 + 1/7 + -1/8 + 1/9 + 1/8 + -1/7 + 1/6 + -1/5
`a,`
`31/23-(7/32+8/23)`
`=31/23-7/32-8/23`
`=(31/23-8/23)-7/32`
`=1-7/32=25/32`
`b,`
`38/45-(8/45-17/51-3/11)`
`=38/45-8/45+17/51+3/11`
`= (38/45-8/45)+17/51+3/11`
`=2/3+17/51+3/11`
`=1+3/11=14/11`
`c,`
`(1/3+12/67+13/41)-(79/67-28/41)`
`= 1/3+12/67+13/41-79/67+28/41`
`= 1/3+(12/67-79/67)+(13/41+28/41)`
`= 1/3+(-1)+1=1/3+(-1+1)=1/3+0=1/3`
`d,`
`1/5+(-1/6)+1/7+(-1/8)+1/9+1/8+(-1/7)+1/6+(-1/5)`
`= (1/5+ -1/5)+(-1/6+1/6)+(1/7+ -1/7)+(-1/8 +1/8)+1/9`
`= 0+0+0+0+1/9=1/9 .`
tinh nhanh:
(45+24-55+76)x(1/5+7/8+7/3+5/7+8/7)
(45+24-55+76)x(1/5+7/8+7/3+5/7+8/7)
=(45+55-24+76)x(1/5+7/8+7/3+5/7+8/7)
=0 x (1/5+7/8+7/3+5/7+8/7)
=0
mình trả lời đầu tiên . mình cũng ko copy
olm ơi , sao olm ko tick đúng cho câu trả lời của em ?
bài 1: tính nhanh
ví dụ 3/8+5/7+45/72+22/77
=(3/8+45/72)+(5/7+22/77)
=1+1
=2
a, 1/2x2/7+3/7:2+1/2:7/2
mình đang cần gấp, cảm ơn
bài 1
4/7+4
3+6/11
3-5/7
21/9-2
15/24+2
63/45-20/25
3/4-2/8
6/7-5/8
37/45-5/9
46/39-11/13
5/12+3/4+1/3
1/2+3/7+11/14
7/10-(1/5+1/4)
15/4-2/3-3/4
`4/7+4`
`=4/7+4/1`
`=4/7+28/7`
`=32/7`
__
`3+6/11`
`=33/11+6/11`
`=39/11`
__
`3-5/7`
`=3/1-5/7`
`=21/7-5/7`
`=16/7`
__
`21/9-2`
`=21/9-18/9`
`=3/9`
`=1/3`
__
`15/24+2`
`=15/24+48/24`
`=63/24`
`=21/16`
__
`63/45-20/25`
`=63/45-4/5`
`=63/45-36/45`
`=27/45`
`=9/15`
__
`3/4-2/8`
`=3/4-1/4`
`=2/4`
__
`6/7-5/8`
`=48/56-35/56`
`=13/56`
__
`37/45-5/9`
`=37/45-25/45`
`=12/45`
`=4/15`
__
`46/39-11/13`
`=46/39-33/39`
`=13/39`
`=1/2`
__
`5/12+3/4+1/3`
`=5/12+9/12+4/12`
`=14/12+4/12`
`=18/12`
`=3/2`
__
`1/2+3/7+11/14`
`=7/14+6/14+11/14`
`=13/14+11/14`
`=24/14`
`=12/7`
__
`7/10-(1/5+1/4)`
`=7/10-(4/20+5/20)`
`=7/10-9/20`
`=14/20-9/20`
`=5/20`
`=1/4`
__
`15/4-2/3-3/4`
`=(15/4-3/4)-2/3`
`=12/4-2/3`
`=3-2/3`
`=9/3-2/3`
`=7/3`
Tính nhẩm:
8 + 1 = … | 7 – 5 = … | 5 + 2 = … | 10 – 6 = … |
28 + 1 = … | 57 – 5 = … | 7 – 35 = … | 52 + 0 = … |
45 + 2 = … | 49 – 6 = … | 7 – 2 = … | 99 – 8 = … |
Lời giải chi tiết:
8 + 1 = 9 | 7 – 5 = 2 | 5 + 2 = 37 | 10 – 6 = 4 |
28 + 1 = 29 | 57 – 5 = 52 | 7 – 35 = 2 | 52 + 0 = 52 |
45 + 2 = 47 | 49 – 6 = 43 | 7 – 2 = 35 | 99 – 8 = 91 |
8+1=9
7-5=2
5+2=7
10-6=4
28+1=29
57-5=52
7-35=-28
52+0=52
OKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK
A = 49 8/23-(5 7/32+14 8/23)
B= 71 38/45-(43 8/45-1 17/57)
45 x 6 =
1 + 1 + 2 + 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 + 7 + 8 + 8 + 9 + 9 =
78 : 5 =...(dư...)
45 : 5 =
x : 5 = 25
45x6=270
1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9
=(1x2)+(2x2)+(3x2)+(4x2)+(5x2)+(6x2)+(7x2)+(8x2)+(9x2)
=2+4+6+8+10+12+14+16+18
=6+6+8+10+12+14+16+18
=12+8+10+12+14+16+18
=20+10+12+14+16+18
=30+12+14+16+18
=42+14+16+18
=56+16+18
=72+18
=90
78:5=15(dư3)
45:5=9
x:5=25
x= 25x5
x= 125
tk nhé
45 x 6 = 270
1 + 1 + 2 + 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 + 7 + 8 + 8 + 9 + 9
= 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18
= ( 2 + 18 ) x 9 : 2
= 90
78 : 5 = 15 ( dư 3 )
45 : 5 = 9
x : 5 = 25
x = 25 x 5
x = 125
\(45x6=270\)
\(1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9\)
\(=1.2+2.2+3.2+4.2+5.2+6.2+7.2+8.2+9.2\)
\(=2+4+6+8+10+12+14+16+18\)
\(=\left(2+18\right)+\left(4+16\right)+\left(6+14\right)+\left(8+12\right)+10\)
\(=10+10+10+10+10\)
\(=10.5\)
\(=50\)
\(78:5=15\left(du3\right)\)
\(45:5=9\)
\(x:5=25\)
\(x=25.5\)
\(x=125\)