
Futeruno Kanzuki 6 hour ago (21:37)
\(\left(5\dfrac{1}{3}2\dfrac{1}{2}\right)+\left(5\dfrac{1}{2}3\dfrac{1}{3}\right)\)
\(=5\dfrac{1}{3}2\dfrac{1}{2}+5\dfrac{1}{2}3\dfrac{1}{3}\)
\(=\left(5\dfrac{1}{3}3\dfrac{1}{3}\right)+\left(5\dfrac{1}{2}2\dfrac{1}{2}\right)\)
\(=2+3=5\)

Futeruno Kanzuki 17 hour ago (09:49)
Call Alice's age is a
Betty's age is b
and Clara is c
Follow the threads , we have :
a + b + c = 29 (1)
b = a + 4 (2)
c = b + 6 (3)
Change (3) , (2) to (1)
a + b + c = a + (a + 4) + (b + 6)
<=> a + (a + 4) + (a + 10) = 29
=> 3a + 14 = 29
=> 3a = 15
=> a = 5
So , Alice's age is 5
Summer Clouds selected this answer.

Duc Luong 12 hour ago (15:25)
Each multiple of 5, increased by 2, ends either in 2 or 7. Each multiple of 6, increased by 3, must be an odd number. Then the only possibilities for the class size are: 7, 17, 27, 37,… . Divide each by 6. The first number that has a remainder of 3 is the required number. That number is 27.

Futeruno Kanzuki 17 hour ago (09:53)
13 = 1.13
4 = 2^{2}
6 = 2.3
BCNN(13 ; 4 ; 6) = 13.2^{2}.3 = 156
Summer Clouds selected this answer.

Vũ Hà Vy Anh Yesterday at 10:52
the area of square is
4 x 4 = 16 (dm2)
the radius of the circle :
4:2=2(dm)
the area of the circle
2 x2 x3,14=12,56(dm2)
the area of shaded region is
16  12,56=3,44(cm2)
No Name selected this answer. 
The area of the square is : 4^{2} = 16 (dm^{2})
The radius of the circle is : 4 : 2 = 2 (dm)
The area of the circle is : \(2^2\pi=4\pi\) (dm^{2})
The area of the shaded region is : \(164\pi\) (dm^{2})

No Name Yesterday at 10:48
the edge of square is 4 dm

Convert : 1 minute 12 seconds = \(\dfrac{6}{5}\)minute ; 1 hour = 60 minutes
The distance the car travels in each minute is : \(1:\dfrac{6}{5}=\dfrac{5}{6}\)(mile)
The distance the car travels in each hour is : \(\dfrac{5}{6}\times60=50\) (miles)
\(\)
Summer Clouds selected this answer. 
Futeruno Kanzuki Yesterday at 14:20
We have the following summary :
1 mile <=> 1p12' = 72' = \(\dfrac{1}{50}h\)
So , in 1 hour , the car can travel :
1mile x 50 <=> \(\dfrac{1}{50}.50h=1h\)
=> x = 50 (mile)

Duc Luong 12 hour ago (15:32)
1 minute 12 seconds = 1.2 minutes = 0.02 hours
In 1 hour, the car can travel:
\(1\div0.02=50\) (miles)
Answer: 50 miles

Let y be that number.Then y x y = 32 x 162
\(\Rightarrow y=\pm\sqrt{32\times162}=\pm72\)
Hence,the answer is 72 or 72

Duc Luong 12 hour ago (15:34)
It is: \(32\times162=5184\) and \(72\times72=5184\)

Nguyễn Phương Linh Yesterday at 20:02
The product of 32 and 162 is:
32 x 162 = 5184
We have: \(\sqrt{5184}\)= 72. So that number is 72.

Futeruno Kanzuki Yesterday at 14:34
\(F=\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{3}}}=\dfrac{1}{1+\dfrac{1}{\dfrac{6}{3}+\dfrac{1}{3}}}=\dfrac{1}{1+\dfrac{1}{\dfrac{7}{3}}}=\dfrac{1}{1+\dfrac{3}{7}}=\dfrac{1}{\dfrac{7}{7}+\dfrac{3}{7}}=\dfrac{1}{\dfrac{10}{7}}=\dfrac{7}{10}=0,7\)
Summer Clouds selected this answer. 
\(F=\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{3}}}=\dfrac{1}{1+\dfrac{1}{\dfrac{7}{3}}}=\dfrac{1}{1+\dfrac{3}{7}}=\dfrac{1}{\dfrac{10}{7}}=\dfrac{7}{10}\)

Duc Luong 12 hour ago (15:38)
\(F=\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{3}}}=\dfrac{1}{1+\dfrac{1}{\dfrac{7}{3}}}=\dfrac{1}{1+\dfrac{3}{7}}=\dfrac{1}{\dfrac{10}{7}}=\dfrac{7}{10}=0.7\)

2 diagonals AC and BD of the square ABCD must be perpendicular
Let O be their intersection or the center of the circle
=> \(\Delta AOB\) is an isosceles triangle \(\Rightarrow AB=\sqrt{2}AO=\sqrt{2}\times\dfrac{AC}{2}=5\sqrt{2}\)(units)
=> The area of the square ABCD is : \(\left(5\sqrt{2}\right)^2=50\) (square units)
Summer Clouds selected this answer. 
Summer Clouds 10 hour ago (17:02)
Added: The square units is 50.

Trần Nhật Quỳnh 24/05 at 19:22
If there are two people at a party, they can shake hands once. There
Như Nguyễn Thị Quỳnh selected this answer.
is no one else left to shake hands with, so there is only one
handshake total.
2 people, 1 handshake
If there are three people at a party, the first person can shake hands
with the two other people (two handshakes). Person two has already
shaken hands with person one, but he can still shake hands with person
three (one handshake). Person three has shaken hands with both of
them, so the handshakes are finished. 2 + 1 = 3.
3 people, 3 handshakes
If there are four people at a party, person one can shake hands with
three people, person two can shake hands with two new people, and
person three can shake hands with one person. 3 + 2 + 1 = 6.
4 people, 6 handshakes
Are you seeing a pattern?
If you have five people, person five shakes four other hands, person
four shakes three other hands, person three shakes two other hands,
and person two shakes one hand. Another way to see it is,
Person 5 Person 4 Person 3 Person 2
4 + 3 + 2 + 1 = 10 handshakes total
====================================================
People at Party Number of Handshakes
2 1
3 1 + 2 = 3
4 1 + 2 + 3 = 6
5 1 + 2 + 3 + 4 = 10
6 1 + 2 + 3 + 4 + 5 = 15
.
.
. n(n1)
n 1 + 2 + ...+ (n1) = 
2
8(81)/2= 28
Each man shakes hands with everyone except his own wife: 284=24
No women shake hands with each other: 24 ((4x3):2)= 18 
Như Nguyễn Thị Quỳnh 24/05 at 19:20
If there are two people at a party, they can shake hands once. There
is no one else left to shake hands with, so there is only one
handshake total.
2 people, 1 handshake
If there are three people at a party, the first person can shake hands
with the two other people (two handshakes). Person two has already
shaken hands with person one, but he can still shake hands with person
three (one handshake). Person three has shaken hands with both of
them, so the handshakes are finished. 2 + 1 = 3.
3 people, 3 handshakes
If there are four people at a party, person one can shake hands with
three people, person two can shake hands with two new people, and
person three can shake hands with one person. 3 + 2 + 1 = 6.
4 people, 6 handshakes
Are you seeing a pattern?
If you have five people, person five shakes four other hands, person
four shakes three other hands, person three shakes two other hands,
and person two shakes one hand. Another way to see it is,
Person 5 Person 4 Person 3 Person 2
4 + 3 + 2 + 1 = 10 handshakes total
====================================================
People at Party Number of Handshakes
2 1
3 1 + 2 = 3
4 1 + 2 + 3 = 6
5 1 + 2 + 3 + 4 = 10
6 1 + 2 + 3 + 4 + 5 = 15
.
.
. n(n1)
n 1 + 2 + ...+ (n1) = 
2
8(81)/2= 28
Each man shakes hands with everyone except his own wife: 284=24
No women shake hands with each other: 24 ((4x3):2)= 18

Trần Nhật Quỳnh 24/05 at 19:22
Như Nguyễn Thị Quỳnh selected this answer.
To be able to buy 9 bottles of fruit juice at the cheapest price, they should appoint 4 people to buy 8 bottles for: (7 + 1) x 4 = 32 (dollars)
The total amount they will pay to buy 9 bottles is: 32 + 7 = 39 (dollars)

Trần Nhật Quỳnh 24/05 at 19:15
Calling the twodigit number written by Anna was: ab then the number Ben wrote was abab
The structural analysis of the number we are:
Abab = 100 x ab + ab = 101 x ab
The result of the division is: abab: ab = 101 x ab: ab = 101

Trần Nhật Quỳnh 24/05 at 14:45
4 horses are there: 4 x 4 = 16 (legs)
11 people are there: 11 x 2 = 22 (legs)
4 horses and 11 people are there: 16 x 22 = 38 (legs)Answer: 38 legs
Trần Nhật Quỳnh selected this answer. 
Vũ Hà Vy Anh 24/05 at 15:57
trần nhật quỳnh tự hỏi tự trả lời để kiếmđiểm hỏi đáp kìa

Duc Luong 11 hour ago (15:53)
You shouldn't do this!
Như Nguyễn Thị Quỳnh
24/05 at 14:34Ten numbers were written on 10 cards as follows:
0

1

2

3

4

5

6

7

8

9

Mr. Zack chose 4 of these cards to form 4  digit odd number. He stood front of a mirror and looked at it up  side  down through the mirror. He saw a new number. If the new number was 720 larger than the orginal one, then the orginal number is …

Trần Nhật Quỳnh 24/05 at 14:39
Because Zack's number is odd, the last digit of this number may be 1 or 9
Như Nguyễn Thị Quỳnh selected this answer.
Because Mr. Zack chose 4 numbers, we type the number 1 (the number of thousands is the same as the unit)
Inferred: Number to find the last digit is 9
When 9 turns 1800 (up  side  down), we get number 6
Inferred: The thousands digit is the number 6
We have: 10  8 = 2
Because the hundreds of new digits minus the tens digit of the old number are 2. Inference: The hundreds digit of the new number is 0 and the tens digit of the old number is 8.
We have: 8  0  1 (remember) = 7
So: The number Zack made at the beginning is: 6089

Trần Nhật Quỳnh 24/05 at 14:28
The number of 4digit numbers is: (9999  1000): 1 + 1 = 9000 (number)
Như Nguyễn Thị Quỳnh selected this answer.
If you do not use numbers 2 and 3, then you have eight digits left to form units, tens and hundreds. Since zeros can not be used to make thousands of digits, there are only seven digits left to make thousands. According to the kernel rule, we have: 8 x 8 x 8 x 7 = 3584 (number)
Inference: A 4digit number containing two digits, or three or both, is 9000  3584 = 5416 (number).

An Duong 24/05 at 15:33
\(f\left(x\right)=x\)
\(\Leftrightarrow\lefta+1ax\right=x\)
\(\Leftrightarrow\left(a+1ax\right)^2=x^2\)
\(\Leftrightarrow\left(a^21\right)x^2+2a\left(a+1\right)x+\left(a+1\right)^2=0\) (*)
if (a = 1) the equation becomes \(4x+4=0\) \(\Leftrightarrow x=2\) (not satisfied: sum of roots is 5/2)
if (a = 1) the equation becomes 0x = 0 (not satisfied sum of roots is 5/2).
Because sum of the roots (*) is 5/2 we infer that:
\(\dfrac{2a\left(a+1\right)}{a^21}=\dfrac{5}{2}\)
\(\Rightarrow9a^2+4a5=0\)
\(a=1,a=\dfrac{5}{9}\)