Write the following cube in the expanded form: $(3a + 4b)^3$

(N/A) To expand $(3a + 4b)^3$,we use the algebraic identity: $(x + y)^3 = x^3 + y^3 + 3xy(x + y)$.
Comparing $(3a + 4b)^3$ with $(x + y)^3$,we get $x = 3a$ and $y = 4b$.
Substituting these values into the identity:
$(3a + 4b)^3 = (3a)^3 + (4b)^3 + 3(3a)(4b)(3a + 4b)$
$= 27a^3 + 64b^3 + 36ab(3a + 4b)$
$= 27a^3 + 64b^3 + 108a^2b + 144ab^2$.