Question

Cum se rezolva x:3=5:x+2

Answer 1

x/3=5/x+2  
x/3-5/x=2
Amplificam:
(x*x-3*5)/3x=2
x*x-15=6x (a*d=c*b)
x*x-6x-15=0
Δ=36+60=96 (b*b+4ac) =>√96=4√6
 
x1=(-b-√Δ)/2a=(6+4√6)/2=3+2√6
x2=(-b+√Δ)/2a=(6-4√6)/2=3-2√6