Odpowiedź:
[tex] {a}^{2} + {b}^{2} = {c}^{2} [/tex]
[tex] {x}^{2} + {9}^{2} = {(7.5 \times 2)}^{2} \\ {x}^{2} + 81 = {15}^{2} \\ {x}^{2} = 225 - 81 \\ {x}^{2} = 144 \: \: \: \: \: | \sqrt{} \\ |x| = 12[/tex]
x=12 v x=-12 ( x=-12 nie spełnia warunków zadania)
x=12
