Question

Calculati:
-2-4-6-...-100

Answer 1

=(-2)+(-4)+(-6)+...+(-100)=
=(-2×1)+(-2×2)+(-2×3)+...+(-2×50)=
=-2(1+2+3+...+50)=

$=-2*\frac{50*51}{2}=$

=-1×50×51=

$\boxed{=-2550}$