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We have : x < -0.8 ⇒ x + 0,8 < 0 ⇒|x + 0.8| = -(x + 0.8)

x < -0.8 ⇒ x < 25 ⇒ |x - 25| = 25 - x

Candle A = -(x + 0.8) - (25 - x) + 1.9

= -x + 0,8 - 25 + x + 1,9

= -x + x - 0,8 - 25 + 1,9

= -25,8 + 1,9

A = -23,8

A = -x - 0.8 - 25 + x + 1.9

A = -23.9

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We have : ab = 8(a + b)

=> 10a + b = 8a + 8b

=> 10a - 8a = 8b - b

=> 2a = 7b

=> a = 7 ; b = 2

So ab is 72

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We have : ƯCLN(140;240) = 20

Dress the largest square can be 20 cm x 20 cm

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We have $(n-1)n(n+1)=(n^2-n)(n+1)=(n^2-n)n+n^2-n=n^3-n^2+n^2-n$

$=n^3-n$

$\Rightarrow n^3=(n-1)n(n+1)+n$ $(1)$

Apply (1) to the expression, we have : 13 + 23 + 33 + ... + 20083

= (1 - 1)1(1 + 1) + 1 + (2 - 2)2(2 + 2) + 2 + ....... + (2008 - 2008) 2008 (2008 - 2008) + 2008

= 1 + 2 + 1.2.3 + 3 + 2.3.4 + ........ + 2008 + 2007.2008.2009

= (1 + 2 + 3 + ...... + 2008) + (1.2.3 + 2.3.4 + ...... + 2007.2008.2009)

= 2017036 + 2007.2008.2009.2010 / 4

= The number to mik not count

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The area around the cube is:
A x a x 4 = a x a x 4
Total cube area is:
A x a x 6 = a x a x 6
The head for the total area larger than the surrounding area is: a x a x 6 - a x a x 4 = 162
The total area larger than the surrounding area is:
A x a x (6 - 4) = a x a x 2
A x a is:
162: 2 = 81 (cm2)
Because 81 = 9 x 9, the edge of the cube is 9 cm
Cubic volume is:
9 x 9 x 9 = 729 (cm3)
Answer: 729 cm3

Good . You Good

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You have : 300 = 22.3.52

The number of integer factors 300 have is :

2.[(2 + 1)(1 + 1)(2 + 1)] = 36

Answer : 36. good

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We have: abcdeg = abc000 + deg
= abc. 100000 + deg
= abc. 99999 + (abc + deg)
Which 99999 is divisible by 37 so abc. and abc + deg is divisible by 37

Candle 99999 is divisible by 37
So the distribution is divided by 37 (ddcm)

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B = 1 + 2 + 3 + ...... + 100

B is numbered as:

100 - 1 + 1 = 100 (số)

Total B is:

(100 x 101) : 2 = 5050

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C = 12 + 22 + 32 + ...... + 1002

= 1.1 + 2.2 + 3.3 + ...... + 100.100

= 1.(2 - 1) + 2.(3 - 1) + 3.(4 - 1) + ...... + 100.(101 - 1)

= 1.2 - 1 + 2.3 - 2 + 3.4 - 3 + ....... + 100.101 - 100

= (1.2 + 2.3 + 3.4 + ...... + 100.101) - (1 + 2 + 3 + ...... + 100)

From the calculated results of A and B we should compute

C = 333300 - 5050

C = 328250

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We have : x < -0.8 ⇒ x + 0,8 < 0 ⇒|x + 0.8| = -(x + 0.8)

x < -0.8 ⇒ x < 25 ⇒ |x - 25| = 25 - x

Candle A = -(x + 0.8) - (25 - x) + 1.9

= -x + 0,8 - 25 + x + 1,9

= -x + x - 0,8 - 25 + 1,9

= -25,8 + 1,9

A = -23,8

A = -x - 0.8 - 25 + x + 1.9

A = -23.9
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EDM Sang copy my post you review time go
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Nguyễn Xuân Sáng you never copy my name again
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Thanks You Nếu Có Thể
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Put A = 1.2 + 2.3 + 3.4 + ....... + 199.200

=> 3A = 1.2.3 - 1.2.3 + 2.3.4 - 2.3.4 + ....... + 199.200.201

=> 3A = 199.200.201

=> A = 199.200.201/3

=> A = 2666600
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That worker makes 3 tools out of time is:

12 hours - 7 hours 30 minute = 4 hours 30 minute = 4,5 hours

The worker makes 1 product time out is :

4,5 : 3 = 1,5 (hours)

Answer : 1,5 hours
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That worker makes 3 tools out of time is:

12 hours - 7 hours 30 minute = 4 hours 30 minute = 4,5 hours

The worker makes a product time out is :

4,5 : 3 = 1,5 (hours)

Answer : 1,5 hours
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Land : A = 1.3 + 3.5 + 5.7 + ...... + 99.101

=> 4A = 1.3.(5 - 1) + 3.5.(7 - 3) + ...... + 99.101.(103 - 99)

=> 4A = 1.3.5 - 1.3.5 + 3.5.7 - 3.5.7 + ...... + 99.100.101

=> 4A = 99.100.101

=> A = 99.100.101/4

=> A = 249975
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From 7m + 5n = 31, we can see that 7m or 5n is even.

- If 7m is even, m is even and prime => m = 2.

=> 5n = 31 - 7 x 2 = 17. n ⋮̸⋮̸ 5, so no numbers sastify the problem.

- If 5n is even, n is even and prime => n = 2.

=> 7m = 31 - 5 x 2 = 21 => m = 3 is a prime number.

The value of: mn + nm = 32 + 23 = 9 + 8 = 17.
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Land A = 1.2 + 2.3 + 3.4 + ....... + 199.200

=> 3A = 1.2.3 - 1.2.3 + 2.3.4 - 2.3.4 + ....... + 199.200.201

=> 3A = 199.200.201

=> A = 199.200.201/3

=> A = 2666600
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We have : $\frac{1}{1.3} + \frac{1}{3.5} + \frac{1}{5.7} + . . . . . . . + \frac{1}{99.101}$

   $= \frac{1}{2} (\frac{2}{1.3} + \frac{2}{3.5} + \frac{2}{5.7} + . . . . . . . + \frac{2}{99.101})$

   $= \frac{1}{2} (1 - \frac{1}{3} + \frac{1}{3} - \frac{1}{5} + . . . . . . + \frac{1}{99} - \frac{1}{101})$

$= \frac{1}{2} (1 - \frac{1}{101})$

   $= \frac{1}{2} . \frac{100}{101}$

   $= \frac{50}{101}$

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From 7m + 5n = 31, we can see that 7m or 5n is even.

- If 7m is even, m is even and prime => m = 2.

=> 5n = 31 - 7 x 2 = 17. n ⋮̸⋮̸ 5, so no numbers sastify the problem.

- If 5n is even, n is even and prime => n = 2.

=> 7m = 31 - 5 x 2 = 21 => m = 3 is a prime number.

The value of: mn + nm = 32 + 23 = 9 + 8 = 17.

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Land A = 1.2 + 2.3 + 3.4 + ....... + 199.200

=> 3A = 1.2.3 - 1.2.3 + 2.3.4 - 2.3.4 + ....... + 199.200.201

=> 3A = 199.200.201

=> A = 199.200.201/3

=> A = 2666600

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Put A = 1.2 + 2.3 + 3.4 + ....... + 199.200

=> 3A = 1.2.3 - 1.2.3 + 2.3.4 - 2.3.4 + ....... + 199.200.201

=> 3A = 199.200.201

=> A = 199.200.201/3

=> A = 2666600

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We have : x < -0.8 ⇒ x + 0,8 < 0 ⇒|x + 0.8| = -(x + 0.8)

x < -0.8 ⇒ x < 25 ⇒ |x - 25| = 25 - x

Candle A = -(x + 0.8) - (25 - x) + 1.9

= -x + 0,8 - 25 + x + 1,9

= -x + x - 0,8 - 25 + 1,9

= -25,8 + 1,9

A = -23,8

A = -x - 0.8 - 25 + x + 1.9

A = -23.9