Q5 of 157 Page 22

Evaluate the following by using the identities:

2.82

∵ 2.82 = (3 – 0.2)2


We know that


(a– b)2 = a2 + b2 – 2a×b


⇒ (3 – 0.2)2= ((3)2 + (0.2)2 – 2×3×0.2)


⇒ (3 – 0.2)2 = 9 + 0.04 – 1.2


⇒ 2.82 = 7.84


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