Question

5m - 3{2n - 4(m - 3n)}

Answer 1

5m- 3{2n-4(m-3n)}
= 5m-3{2n-4m+12n}
= 5m-6n+12m+12n
=17m+6n [ANSWER]

Answer 2

$5m - 3(2n - 4(m - 3n)) \\ \\ = 5m - 3(2n - 4m + 12n) \\ \\ = 5m - 3(14n - 4m) \\ \\ = 5m - 42n + 12m \\ \\ = 17m - 42n$
hope it helps..