2. x= pret initial
x +[tex] \frac{15}{100} [/tex] * x =460 aducem la numitor comun
100x/100 +15x/100= 46000/100 scapam de numitor
100x+15x=46000
115x= 46000
x=46000: 115
x=400
3. P= l+l+ l= 3*l ( triunghiul echilateral are toate laturile egale)
3*l = 36
l= 36:3
l=12
A= [tex] \frac{ l^{2} \sqrt{3} }{4} [/tex]
A= [tex] \frac{144 \sqrt{3} }{4} [/tex]
A=[tex]36 \sqrt{3} [/tex] cm^2