<=>\(\frac{\left(x+2\right)2}{2}=110\Leftrightarrow x+2=110\Leftrightarrow x=108\)

số số trong dãy số là:

(x-2):2+1=x/2

=>2+4+...+x=(x+2)x:4=110

=>x(x+2)=110.4=440

=>x^2+2x-440=0

=>x^2+22x-20x-440=0=>x(x+22)-20(x+22)=0

=>(x-20)(x+22)=0

=>x-20=0 =>x=20

hoặc x+22=0=>x=-22 (loại)

vâỵ x=20

Ta có:

      [(X - 2) : 2 + 1] x  (X + 2) : 2 = 110

=>  [(X - 2) : 2 + 1] x  (X + 2) = 110 x 2 = 220

=>   (X² + 2X) : 2 = 220

=>   X² + 2X = 220 x 2 = 440

=> X (X + 2) = 440

=> X = 20

VẬY X = 20

20, mk ko biết cách tính , sorry

\(\frac{x+110}{100}+\frac{x+8}{102}+\frac{x+6}{104}=\frac{x+4}{106}+\frac{x+2}{108}\)

\(\Leftrightarrow\frac{x+110}{100}+\left(\frac{x+8}{102}+1\right)+\left(\frac{x+6}{104}+1\right)=\left(\frac{x+4}{106}+1\right)+\left(\frac{x+2}{108}+1\right)\)

\(\Leftrightarrow\frac{x+110}{100}+\frac{x+110}{102}+\frac{x+110}{104}=\frac{x+110}{106}+\frac{x+110}{108}\)

\(\Leftrightarrow\frac{x+110}{100}+\frac{x+110}{102}+\frac{x+110}{104}-\frac{x+110}{106}-\frac{x+110}{108}=0\)

\(\Leftrightarrow\left(x+110\right)\left(\frac{1}{100}+\frac{1}{102}+\frac{1}{104}+\frac{1}{106}+\frac{1}{108}\right)=0\)

\(\Leftrightarrow x+110=0\) (vì \(\frac{1}{100}+\frac{1}{102}+\frac{1}{104}-\frac{1}{106}-\frac{1}{108}>0\))

\(\Leftrightarrow x=-110\)

Vậy \(x=-110\)

mn giải hộ mik ik

Số số hạng: (2x - 2) : 2 + 1 = x (số hạng)

=> \(2+4+6+8+...+2x=110\)

<=> \(\frac{\left(2x+2\right).x}{2}=110\)

<=> 2x.(x+1) = 2.110

=> x.(x+1) = 110

<=> x.(x+1) = 10.(10+1)

<=> x = 10

\(2x+\left(1+2+3+...+100\right)=15150\)

\(2x+\left[\left(1+100\right)+\left(2+99\right)+...+\left(50+51\right)\right]=15150\)

\(2x+\left[101+101+...+101\right]=15150\)CÓ 50 SỐ 101

\(2x+\left[101\times50\right]=15150\)

\(2x=15150:5050\)

\(2x=3\)

\(x=3:2\)

\(x=1.5\)

a, 2x + (1+2+3+4+...+100) = 15150 

=> 2x + \(\frac{\left(1+100\right).\left[\left(100-1\right)+1\right]}{2}\)= 15150 

=> 2x + \(\frac{101.100}{2}\)= 15150 

=> 2x + 5050 = 15150 

=> 2x             = 15150 - 5050 

=> 2x             = 10100

=> x              =  10100 : 2 

=> x              = 5050 

Vậy x = 5050 

b, .(x+1)+(x+2)+(x+3)+(x+4)+(x+5)+(x+6)+(x+7)+(x+8)=36 

=> (x + x + x + x +x + x +x +x ) + (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8) = 36 

=> 8x + 36 = 36 

=> 8x         = 0 

=>  x          = 0 

Vậy x = 0 

c, 0+0+4+6+8+...+2x=110 

Sửa đề :0 + 2 + 4 + 6 + 8 + ... + 2x = 110 = 2 + 4 + 6 + 8 + ... + 2x = 110 

SSH  : \(\frac{\left(2\text{x}-2\right)}{2}+1=x-1+1=x\)

Tổng : \(\frac{\left(2\text{x}+2\right).x}{2}=110\Leftrightarrow\frac{2.\left(x+1\right).x}{2}=110\)

                                                    \(\Leftrightarrow\left(x+1\right)x=110\)

                                                     \(\Leftrightarrow\left(10+1\right).10=110\)

 => x = 10 

Vậy x = 10 

#)Giải :

a) 2x + ( 1 + 2 + 3 + 4 + ... + 100 ) = 15150

=> 2x + [ ( 100 + 1 ) x 100 : 2 ] = 15150

=> 2x + 5050 = 15150

=> 2x = 10100

=> x = 5050

b) ( x + 1 ) + ( x + 2 ) + ... + ( x + 8 ) + ( x + 9 ) = 36

=> ( x + x + x + ... + x ) + ( 1 + 2 + 3 + ... + 9 ) = 36

=> ( x + x + x + ... + x ) + 45 = 36

=> ( x + x + x + ... + x ) = -9

=> x = -1

c) Đề kiểu j v ? xem lại đi bạn ???

Số số hạng là: \(\dfrac{2x-2}{2}+1=x-1+1=x\left(số\right)\)

Tổng của dãy số 2;4;6;...;2x là;

\(\left(2x+2\right)\cdot\dfrac{x}{2}=x\left(x+1\right)\)

2+4+6+8+...+2x=110

=>x(x+1)=110

=>\(x^2+x-110=0\)

=>\(\left(x+11\right)\left(x-10\right)=0\)

=>\(\left[{}\begin{matrix}x=-11\left(loại\right)\\x=10\left(nhận\right)\end{matrix}\right.\)