Question

Factorise the following:
2a³ + 5a²b - 12ab²

Answer 1

2a³ + 5a²b - 12ab²
= 2a³ + 8a²b - 3a²b - 12ab²
= 2a²(a + 4b) - 3ab(a + 4b)
= (a + 4b)(2a² - 3ab)
= (a + 4b)a(2a - 3b)
= a(a + 4b)(2a - 3b).