i. Here, A = 2a and B = 3b
∴ (2a – 3b)2 = (2a)2 – 2 × 2a × 3b + (3b)2 …. [(A – B)2 = A2 – 2AB + B2 ]
= 4a2 – 12ab + 9b2
ii. Here, a = 10 and b = y
(10 + y)2 = 102 + 2 × 10xy + y2 …. [(a + b)2 = a2 + 2ab + b2 ]
= 100 + 20y + y2
iii. Here, a = and b = q/4
(p/3 + q/4)2 = (p/3)2 + 2 x p/3 x q/4 + (q/4)2…. [(a + b)2 = a2 + 2ab + b2 ]
iv. Here, a = y and b = 3/y
(y - 3/y)2 = y2 - 2 x (y) x 3/y + (3/y)2 …. [(a – b)2 = a2 – 2ab + b2
= y2 - 6 + 9/y2