Question

Jumatatea jumatatii unui numar adunata cu treimea altui numar da 42.Sa se afle numerele ,stiind ca primul reprezinta doua treimi din al doilea

Answer 1

Fie a si b numerele
1/2· 1/2 ·a +1/3 ·b=42;
1/4 ·a+ 1/3 ·b=42;
a=2/3 ·b;
1/4 ·2/3·b +1/3 ·b=42;
2/12 ·b+1/3 ·b=42;
1/6 ·b+ 2/6 ·b=42;
3/6 ·b=42;
1/2 ·b=42;
b=42: 1/2;
b=42· 2=84;
a=2/3 ·84=168/3=56;
Verificare:
1/2· 1/2· 56+ 1/3· 84=14+28=42;

Answer 2

Notam cu X si Y cele doua numere
a : 2 : 2 + b : 3 = 42 |×12
3a + 4b = 504
a = 2b/3
3×2b/3 +4b = 504 |×3
6b + 12b = 1512
18b = 1512
b = 1512 : 18
b = 84
a = 2×84/3 = 168/3 = 56

a = 56
b = 84