Question

Daca a,b,c sunt numere naturale asfel incat a+b+c=57 si 2a+b+2c=73, calculati (a+c)·(5·a+2·b+5·c)

Answer 1

73=2a+b+2c=(a+b+c)+(a+c)=57+(a+c), deci 
a+c=16 

5a+2b+5c=2(2a+b+2c)+(a+c)=2*73+16=162 deci rezultatul cerut este: 

16*162=2592