Question

Găsiți suma tuturor nr naturale care împărțite la 4 dau catul 7! Urgentt! Dau coroana+15 puncte!

Answer 1

x:4=7 rest r=> x=4*7+r, unde r<4=>
x=28+r, unde r=0,1,2,3
x=28+0=28
x=28+1=29
x=28+2=30
x=28+3=31
Suma=28+29+30+31=118

Answer 2

d:4=7,r
d=4x7+r
r<4
r={0,1,2,3}
d:4=7 rest 0
d=4x7+0
d=28
d:4=7 rest 1
d=4x7+1
d=28+1
d=29
d:4=7 rest 2
d=4x7+2
d=28+2
d=30
d:4=7 rest 3
d=4x7+3
d=28+3
d=31
S=28+29+30+31
S=(29+31)+(28+30)
S=60+58
S=118