tolong dong, tolong tolong

[tex] {a}^{n} + {a}^{m} = {a}^{n + m} \\ tinggal \: ditambah \\ {a}^{( - 2 + 5)} {b}^{ (- 2 + - 1 + - 3)} \\ {a}^{3} {b}^{ - 6} [/tex]