Answer:
[tex]9 \sqrt{x} = \sqrt{12} + \sqrt{147} \\ = > \sqrt{x} = \frac{ \sqrt{12} + \sqrt{147} }{9} \\ = > x = {(\frac{ \sqrt{12} + \sqrt{147} }{9} )}^{2} \\ = > x = ( \frac{15.58}{9} )^{2} \\ = > 3[/tex]