Expand the following:

(i) (3

(i) Given that: (3a – 2b)3 = [3a + (−2b)]3


= (3a)3 + (−2b)3 + 3(3a)2(−2b) + 3(3a)(−2b)2


[∵ (a + b)3 = (a3 + b3 + 3a2b + 3ab2)]


= 27a3 – 8b3 – 54a2b + 36ab2


(ii). given



[∵ (a + b)3 =(a3 + b3 + 3a2b + 3ab2)]


=


(iii). Given that: (4 −13x)3


= (4)3 + (−13x)3 + 3(4)2(−13x) + 3(4) (−13x)2


[∵ (a + b)3 =(a3 + b3 + 3a2b + 3ab2)]


= 64 −127x3 −16x + 43x


31