a + ( a + 1 ) + ( a + 2 ) + ....... + ( a + 9 ) = 445
10 x a + ( 1 + 2 + 3 + ...... + 9 ) = 445
10 x a + 9 x 10 : 2 = 445
10 x a + 45 = 445
10 x a = 445 - 45
a = 400 : 10
a = 40 → primul nr.
40 + 1 = 41 → al doilea nr.
41 + 1 = 42; 42 + 1 = 43; 44; 45; 46; 47; 48 si 49
Verific:
40 + 41 + 42 + 43 + 44 + 45 + 46 + 47 + 48 + 49 = 445
= 40 + ( 41 + 49) + ( 42 + 48) + ( 43 + 47 ) + ( 44 + 46 ) + 45 =
= 4 x 90 + 40 + 45
= 360 + 40 + 45 =
= 445
Raspuns: 40; 41; 42; 43; 44; 45; 46; 47; 48; 49 → numerele consecutive
