[tex]PYTHAGOREAN THEOREM\\c^{2} = a^{2} + b^{2}\\ b^{2}=c^{2} -a^{2}\\ a^{2} =b^{2}-c^{2}[/tex]
1) x=9, because we can use the Pythagorean theorem, x^2 + 144 = 225, x^2 = 81
2) [tex]x=3\sqrt{8}[/tex], because 6^2 +6^2 = 72, [tex]\sqrt{72} = 3\sqrt{8}[/tex]
3) [tex]x=2\sqrt{3}[/tex], because [tex]x^{2} +7=19\\x^{2} =12\\x= 2\sqrt{3}[/tex]
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