Question

simplify (2a + 3b)^3 + (2a - 3b)^3​

Answer 1

Step-by-step explanation:

(2a + 3b)^3 + (2a - 3b)^3

=(2a + 3b + 2a - 3b)((2a + 3b)^2+ (2a - 3b)^2-(2a + 3b)(2a - 3b))

=4a(2(4a^2+9b^2)-(4a^2-9b^2))

since (x+y)^2+(x-y)^2=2(x^2+y^2)

=4a(a^2-27b^2)

=4a^3-108ab2