Răspuns:
[tex]x=\frac{13}{25}[/tex]
Explicație pas cu pas:
[tex]\sqrt{5(x+4)} +2\sqrt{5(x-2)} =\sqrt{15} \\(\sqrt{5(x+4)} +2\sqrt{5(x-2)})^2 =(\sqrt{15})^2\\5*x+4+4*5*x-2=15\\5x+4+20x-2=15\\25x+4-2=15\\25x+2=15\\25x=13\\x=\frac{13}{25}[/tex]
Succes! :)