This involves the Cube of a Sum:
(2s + 3)3
= (2s)3 + 3(2s)2(3) + 3(2s)(3)2 + (3)3 = 8s3 + 36s2 + 54s + 27
= (2s)3 + 3(2s)2(3) + 3(2s)(3)2 + (3)3
= 8s3 + 36s2 + 54s + 27