👤

calculati sumele:
a) (3+5+7+...+2015) -2-4-6-...-2014
b) (2+4+6+...+2016) -1-3-5-...-2015
Dau coroana !!! Plsssss!!!


Răspuns :

(3+5+7+...+2015)-2-4-6-...-2014= =( 3-2)+(5-4)+(7-6)+...+(2015-2014)= =1+1+1+....+1=1 x 1007 = 1007 (2015-3):2+1=1007