Question

VA ROGGG
Scrie nr naturale divizibile cu 3 de forma 1a, a5, 36ab, 4a9b, 1ab7

Answer 1

12 ,35,3681,4392,1026  (pentru ca un numar sa fie divizibil cu 3 suma tuturor cifrelor nr trebuie sa se împarta la 3)

Answer 2

1a, a5, 36ab, 4a9b, 1ab7

1a  divizibil cu 3 => a={2,5,8}

1a={12,15,18}

 

a5  divizibil cu 3=>a={1,4,7}

a5={15,45,75}

 

36ab divizibil cu 3=>a+b={0,3,6,9,12,15,18}

a={0,1,2,3,4,5,6,7,8,9} si b={0,1,2,3,4,5,6,7,8,9}

36ab={3600, 3603, 3606, 3609, 3612, 3615…… 3699}

 

4a9b divizibil cu 3=>a+b={2,5,8,11,14,17}

a={0,1,2,3,4,5,6,7,8,9} si b={0,1,2,3,4,5,6,7,8,9}

4a9b={4092, 4095, 4098, 4191, 4194, 4197,4290, 4293, 4296, 4299, 4392, 4395, 4398, 4491,4494, 4497, 4590, 4593, 4596, 4599, 4692, 4695, 4698, 4791, 4794, 4797, 4890,4893, 4896,  4899, 4992, 4995, 4998}

 

1ab7 divizibil cu 3 => a+b={1,4,7,10,13,16}

a si b ={0,1,2,3,4,5,6,7,8,9}

1ab7={1017, 1047, 1077, 1107, 1137, 1167, 1197, 1227, 1257, 1287, 1317, 1347, 1377, 1407, 1437, 1467, 1497, 1527, 1557, 1587, 1617, 1647, 1677, 1707, 1737, 1767, 1797, 1827, 1857, 1887, 1917, 1947, 1977}