Question

Calculati suma 1+2+3+4+5+...+50

Answer 1

S=(50+1) *50 /2= 51*50 /2=2550/2=1275

Answer 2

$\displaystyle 1+2+3+4+5+...+50= \frac{50(50+1)}{2} = \frac{50 \times 51}{2} = \frac{2550}{2} =1275$