<=> 100x + (1 + 2 + 3 + .... .+ 100) = 5750

<=> 100x + 5050 = 5750

=> 100x = 700

=> x = 7

(x+1)+(x+2)+(x+3)+(x+4)+...+(x+100)=5750

(x+x+x+...+x)+(1+2+3+4+...+100)     =5750

100x             +5050                         =5750

100x                                               =5750-5050

100x                                               =700

     x                                               =700:100

     x                                               =7

( x +1 )+ ( x + 2 ) + ... +  ( x + 100 ) = 5750

( x + x + x + ...+ x ) + ( 1 + 2 + ... + 100 ) = 5750

x * 100 + 5050 = 5750

x * 100 = 700

x = 7

đặt x ra ngoài chung còn trong ngoặc là 1+2+3+...+99+100

\(\left(x+1\right)+\left(x+2\right)+...+\left(x+100\right)=5750\)

\(\left(x\cdot100\right)+\left(1+2+...+100\right)=5750\)

\(\left(x\cdot100\right)+\left(100+1\right)\cdot\frac{100}{2}=5750\)

\(\left(x\cdot100\right)+101\cdot50=5750\)

\(\left(x\cdot100\right)+5050=5750\)

\(x\cdot100=5750-5050\)

\(x\cdot100=700\)

\(x=700\div100\)

\(x=7\)

Ta có: ( x+1)+(x+2)+(x+3)+.....+(x+99)+(x+100)=5750

<=>(x+x+x+....+x+x)+(1+2+3+..+99+100)=5750

<=> 100x+5050=5750

=>100x=5750-5050

=>100x=700

=>x=700:100

=>x=7

Vậy x=7

 hoặc mở câu hỏi tương tự tham khảo.

thank you

(x+1)+(x+2)+(x+3)+.......+(x+99)+(x+100)=5750

(x+x+x+...+x)+(1+2+3+...+100) = 5750

100x+5050 = 5750

100x = 5750-5050

100x = 700

x = 700 : 100

x = 7

a) 2-(x+3) = 1+2+3+...+99

1+2+3+...+99 → có 99 số hạng

2-(x+3) = (1+99).99 : 2 

2-(x+3) = 4950

x+3 = 2 + 4950 

x+3 = 4952

x = 4952 - 3

x = 4949

b) (x+1)+(x+2)+...+(x+100) = 5750

→ có 100 cặp

(x+x+x+...+x) + ( 1+2+3+...+100 ) = 5750

=> 100x + 5050 = 5750

100x = 5750 - 5050

100x = 700

x = 700 : 100

x = 7

 0o0 Nguyễn Đoàn Tuyết Vy 0o0 bà kêu tui học tốt có nghĩa là học giốt đúng ko

b)(x+1)+(x+2)+(x+3)+(x+4)+...............+(x+100)=5750

(x+x+x+x+...+x) + (1+2+3+4+...+100) = 5750

     100x             +           5050           = 5750

                       100x                          = 5750 - 5050

                       100x                          = 700

                         x                             = 700 : 100

                         x                             = 7

Vậy ...

Ta có: \(\left(x+1\right)+\left(x+2\right)+...+\left(x+100\right)=5750\)

\(\Leftrightarrow100x+5050=5750\)

\(\Leftrightarrow100x=700\)

hay x=7

x=7

tham kharo : https://olm.vn/hoi-dap/detail/89184552036.html

(x+1)+(x+2)+...+(x+100)=5750

(x+x+...+x)+(1+2+3+...+100)=5750

100x+5050=5750

100x=5750-5050

100x=700

x=700/100

x=7

\(\Leftrightarrow100x+5050=5750\)

hay x=7

(x+1) + (x+2) + (x+3) +....+ (x+100) = 5750

x + 1 + x + 2 + x + 3 +...+ x + 100 = 5750

(x + x + x +...+ x) + (1 + 2 + 3 +...+ 100) = 5750

100x + 5050 = 5750

100x = 5750 - 5050

100x = 700

x = 700 : 100

x = 7

=>100x+5050=5750

=>100x=700

=>x=7