Question

Calculați:
2+4+6+...+200=?
va rog, am nevoie de ajutor!

Answer 1

=2×1+2×2+2×3+...+2×100=

=2(1+2+3+...+100)

$=2*\frac{100*101}{2}=$

=100×101=

=10.100

Answer 2

2+4+6+...+200=
=100×(2+200):2=
=20200:2
=10100