Question

1pe3 plus 2pe3 plus3pe3... 85pe3​

Answer 1

Răspuns:

$\boxed{\frac{3655}{3}}$

Explicație pas cu pas:

$\displaystyle{ \frac{1}{3} + \frac{2}{3} + \frac{3}{3} + ..... + \frac{85}{3} = \frac{1 + 2 + 3 + .... + 85}{3} }$

1 + 2 + 3 + ..... + 85 = (85 + 1) × 85 ÷ 2

= 86 ÷ 2 × 85

= 43 × 85

= 3655

$\displaystyle{ \rightarrow \frac{1 + 2 + 3 + .... + 85}{3} = \frac{3655}{3} }$