Răspuns:
[tex]x=5^{2n} *(12^2)^{n+1} +12^{2n} *(5^2)^{n+1} \\\\x=5^{2n} *12^{2n+2} +12^{2n} *5^{2n+2} \\\\dam.factor.comun\\\\x=5^{2n} *12^{2n} (1*12^2+1*5^2)\\\\x=5^{2n} *12^{2n}(12^2+5^2)\\\\x=(5*12)^{2n} *(144+25)\\\\x=[(5*12)^n]^2*169\\\\x=(60^n)^2*13^2\\\\\sqrt{x} =\sqrt{(60^n)^2*13^2} \\\\\sqrt{x} =60^n*13[/tex]
