a)
[tex] {6}^{2} + {x}^{2} = {10}^{2} \\ 36 + {x}^{2} = 100 \\ {x}^{2} = 64 \\ x = \sqrt{64} \\ x = 8[/tex]
b)
[tex] {12}^{2} + {16}^{2} = {2x}^{2} \\ 144 + 256 = {2x}^{2} \\ 400 = {2x}^{2} | \div 2 \\ {x}^{2} = 200 \\ x = \sqrt{200} \\ x = \sqrt{2 \times 100} \\ x = 10 \sqrt{2} [/tex]
