1. 8a2 + b2 + 12a2b + 6ab2
  2. 8a2 - b3 + 12a2b + 6ab2
  3. 27 -125a3 - 135a + 225a2
  4. 64a2 - 27b2 - 144a2b + 108ab2
  5. 27p3 - 1/216 - 9/2p2 + 1/4p

Report
Question

(i) Using identity,

(a + b)3 = a3 + b3 + 3a2b + 3ab2

8a3 + b3 + 12a2b + 6ab2

= (2a)3 + b3 + 3 (2a) (2b) + 3 (2a) (b)2

= (2a + b)3

= (2a + b) (2a + b) (2a + b)

(ii) Using identity,

(a + b)3 = a3 + b3 + 3a2b + 3ab2

8a3 – b3 – 12a2b + 6ab2

= (2a)3 – b3 – 3 (2a)2b + 3 (2a) (b)2

= (2a – b)3

= (2a – b) (2a – b) (2a – b)

(iii) Using identity,

(a + b)3 = a3 + b3 + 3a2b + 3ab2

27 – 125a3 – 135a + 225a2

= 33 – (5a)3 – 3 (3)2(5a) + 3 (3) (5a)2

= (3 – 5a)3

= (3 – 5a) (3 – 5a) (3 – 5a)

(iv) Using identity,

(a + b)3 = a3 + b3 + 3a2b + 3ab2

64a3 – 27b3 – 144a2b + 108ab2

= (4a)3 – (3b)3 – 3 (4a)2 (3b) + 3 (4a) (3b)2

= (4a – 3b)2

= (4a – 3b) (4a – 3b) (4a – 3b)

(v) Using identity,

(a + b)3 = a3 + b3 + 3a2b + 3ab2

27p3 - 1/216 - 9/2p2 + 1/4p

= (3p)3 – (1/6)3 – 3 (3p)2 (1/6) + 3 (3p) (1/6)2

= (3p - 1/6)3

= (3p - 1/6) (3p - 1/6 (3p - 1/6)

solved 5
wordpress 4 mins ago 5 Answer 70 views +22

Leave a reply

 Prev question

Next question