Question

aflati suma tuturor numerelor naturale care impartite la 4 dau catul egal cu restul

Answer 1

n:4=c + r
r<4
c=r
r=1 ; 2 ; 3
c=1; 2 ; 3
n=cx4+r
n:4=1 rest 1
n=1x4+1=4+1 ⇒ n=5
n:4=2 rest 2
n=2x4+2=8+2 ⇒n=10
n:4=3 rest 3
n=3x4+3=12+3 ⇒n=15
5+10+15=30