Tentukan nilai a Tolong buat besok

[tex]t {}^{2} = s{}^{2}-a{}^{2} \\ 10{}^{2} = (13a) {}^{2}-(12a) {}^{2} \\ 100 = 169a{}^{2}-144a {}^{2} \\ 100=25a{}^{2} \\ 25a {}^{2} = 100 \\ a {}^{2} = \frac{100}{25} \\ a {}^{2} = 4 \\ a = \sqrt{4} \\ a = 2[/tex]