Question

calculati suma S=6+12+ 18+ 24+ ............+ 600

Answer 1

S=6+12+18+24+...+600=6(1+2+3+...+100)
=6(101*100:2)=6(101*50)=6*5050=30300

Answer 2

vom rezolva cu ajutorul sumei Gauss

1+2+3+....+n= nx(n+1)/2

S=6+12+18+24+.....+600 scoatem factor comun 6

S= 6(1+2+3+4+....+100)= 6x100x101/2=30300