Question

Determina x si y numere naturale daca:
a) x•y=42
b) x•(y+3) =21
c) x(x+2) =24
d) (x-3)(y-5)=0

Answer 1

a).x*y=42
   x=21
  y=2
  21*2=42

b).x(y+3)=21
   x=3
   y=4
  3*(4+3)=21
  3*7=21

c).x(x+2)=24
   x=4
   4*(4+2)=24
   4*6=24

d).(x-3)(y-5)=0
    x=3
    y=5

Answer 2

a)
Perechi soluții (1,42),(2,21),(3,14),(6,7)

b)
x=1, y+3=21=> y=18
x=3, y+3=7=> y=4
x=7, y+3=3=>y=0