Question

Efectuati!
(-1)+2+(-3)+4+(-5)+...+(-19)+20
Ajutati-ma, va rog!

Answer 1

Answer:10

Explanation:

2+4+6+.....+20- (1+3+5+7+...+19)=(2-1)+(4-3)+(6-5)+....+(20-19)=1+1+...+1 ( de 10 ori= 10 times)

=10