Question

Determinati numerele naturale a si b stiind ca suma lor este 431 si 2×a+5×b=1696

Answer 1

a + b = 431    

2 × a + 5 x b = 1 696

2 × a + 2 × b + 3 × b = 1 696

2 × ( a + b ) + 3 × b = 1 696

2 × 431 + 3 × b = 1 696

862 + 3 × b = 1 696

3 × b = 1 696 - 862

3 × b = 834

b = 834 : 3 ⇒   b = 278

a = 431 - 278

a = 153