Question

Tìm x biết :  (x+83)+(x+82)+...+x = 4074

Answer 1

\(\left(x+83\right)+\left(x+82\right)+...+x=4074\)

\(\Rightarrow\left(x+x+...+x\right)+\left(83+82+...+1\right)\)

\(\Rightarrow84x+3486=4074\)

\(84x=4074-3486\)

\(84x=588\)

\(x=588:84\)

\(x=7\)

Answer 2

(x + 83) + (x + 82) + ..... + x = 4074

<=> (x + x + x + .... + x) + (1 + 2 + 3 + ..... + 83) = 4074 ( có [(x + 83) - x ] + 1 = 84 số x )

<=> 84x + 83.(83 + 1) : 2 = 4074

<=> 84x + 3486 = 4074

<=> 84x = 588

=> x = 7

Vậy x = 7