Question

Perimetrul=32
Aria=60
Intr-un dreptunghi
L=?
l=?
Ajutor​

Answer 1

P=2(L+l)=32 cm/:2=>L+l=16 cm

L+l=16=>l=16-L

L*l= 60

_____

(16-L)*L=60

-L^2+16L-60=0/*(-1)

L^2-16L+60=0

delta=b^2-4ac=(-16)^2-4*1*60=16

L1=(-b+√delta)/2a=(16+4)/2*1=20/2=10

L2=(-b-radical)2a=(16-4)/2*1=6

Dacă L=10 cm=>l=16 cm-10 cm=6 cm (Da, L>l)

Dacă L=6 cm=>l=16 cm-6 cm=10 (fals; L<l)

L=10 cm, l=6 cm