Question

Intr-un dreptunghi avand perimetrul egal cu 20 cm cunoastem ca {L,l} d.p {3,2}. Aflati aria dreptunghiului.

Answer 1

$\frac{L}{3} + \frac{l}{2} = k$
L= 3k
l=2k
P= 20cm=2L+2l= 2·3k+2·2k= 6k+4k=10k
k=20:10=2
L= 3·2= 6cm
l= 2·2=4cm
Aria=L·l=6·4=24cm²