Question

buna , ma puteti ajuta? voi adauga mai multe ex. :
1. x∧2 supra y∧2 ∈ N , determinati xy cu bara deasupra

2. daca a+b+c = 43  
          si   3a+2b+c=72
   se cere : E=(2a+b)*(4a+3b+26)

3. determinati cifrele a , b , c daca 3 * ab=bc cu bara deasupra ambele

Answer 1

1. $\frac{x^{2}}{y^{2}} = ( \frac{x}{y} )^{2$ 
  $x$ se divide cu y  daca x si y sunt cifre atunci  $xy$ ∈{11.21.22.33.31.44.42.41.55.51.66.63.62.61.77.71.88.84.82.81.99.
93.91}
2.
3a+2b+c=72
a+b+c=43
Noi putem sa le scadem obtinem:
2a+b=29
Si le adunam obtinem:
4a+3b+2c=115
(2a+b)*(4a+3b+2c)=29*115=3335