Answer:
x = 12
Step-by-step explanation:
[tex] {x}^{2} = {6}^{2} + {( \sqrt{18 \times 6} )}^{2} \\ \\ {x}^{2} = 36 + {( \sqrt{108} )}^{2} \\ \\ {x}^{2} = 36 + 108 \\ \\ {x}^{2} = 144 \\ \\ x = \sqrt{144} \\ \\ x = 12[/tex]
