Question

x=2(1+2+3+...+98)+99​

Answer 1

Răspuns:

Explicație pas cu pas:

x=2(1+2+3+...+98)+99

x = 2 * 98*99/2 + 99

x = 98*99 + 99

x = 99 * 99

Answer 2

$\it x=2(1+2+3+\ ...\ +98) +99 \Rightarrow x=\not2\cdot\dfrac{98\cdot99}{\not2}+99=\\ \\ \\ =98\cdot99+99=99(98+1)=99\cdot99=9801$