Question

simplify-
1. (a+3)^3 + (a-3)
2. (2x-5y)^3 - (2x+5y)^3

Answer 1

$a \times a \times a + 81 + 3a \times a \times 3 + 3a \times 9 + a - 3$
$a \times a \times a + 9a \times a + 28a + 78$