Question

plz help mates.....

Answer 1

a.
$25 {a}^{2} - 20a - 15a + 12 \\ 5 {a}^{} (5a - 4) - 3(5a - 4) \\ (5a - 3)(5a - 4).$
b)
$25 {a}^{2} + 25a - 12a - 12 \\ 25a(a + 1) - 12(a + 1) \\ (25a - 12)(a + 1)$
hope it will help you.