Răspunsuri

2014-04-15T09:42:56+03:00
L=25*l
P=2*L+2*l , P=72
A=?

L= \frac{25}{100} *L = \frac{1}{4} *l

P=2* \frac{1}{4} + 2 *l
P= \frac{1}{2} + 2l ( amplificam cu 2)
P= \frac{1}{2} + \frac{2}{2} l
72= \frac{3}{2} l
l=72* \frac{3}{2}  

De unde ai scos 2*1/4? poate 2*1/4*l. De acolo s-a dus tot
2014-04-15T10:20:16+03:00
L=25l/100
L=l/4

L+L+l+l=72
l/4+l/4+l+l=72. Amplificam cu 4 ca sa aducem la acelasi numitor
l+l+4l+4l=288
10l=288
l=288/10
l=28.8

L=28.8/4
L=7.2

Aria=L*l
Aria=7.2*28.8
Aria=207.36