Question

determinati numerele naturale de forma 2x2y divizibile cu 3

Answer 1

(2+ x + 2 + y) = (4 + x + y) divizibil cu 3 ⇒ x+y = 2     x∈{0,1,2},  y∈{2,1,0}
n ∈{2022, 2121, 2220}
x+y = 5    x∈{0,1,2,3,4,5}  y∈{5,4,3,2,1,0}
 n∈{2025,2124,2223,2322,2421,2520}
x+y = 8  x∈{0,1,2,3,4,5,6,7,8}  y∈{8,7,6,5,4,3,2,1,0}
n ∈{ 2820,2721,2622,2523,2424,2325,2226,2127,2028}