Question

Tìm x biết

1+2+3+...+x=500500

Answer 1

\(1+2+3+....+x=500500\)

\(\Leftrightarrow\left(1+x\right).x\div2=500500\)

\(\Leftrightarrow\left(1+x\right).x=500500.2\)

\(\Leftrightarrow\left(1+x\right).x=1001000\)

\(\Leftrightarrow\left(1+x\right).x=1001.1000\)

\(\Leftrightarrow x=1000\)

Vậy x = 1000 

Answer 2

x>0

ta có 1+2+3+...+x= (x+1).x /2

Nên (x+1)x/2=500500

     (x+1)x    =500500.2=1001000

     x²+x   - 1001000=0

\(\orbr{\begin{cases}x=1000\\x=-1001\end{cases}}\)

Vậy x=1000

Answer 3

bằng 1000 bạn nhé 

kich mình nha

 

Answer 4

= 100 nhé 

Answer 5

Thank you nka