Using identities, evaluate.

(i)


(ii)


(iii)


(iv)


(v)


(vi)


(vii)


(viii)


(ix)


(i) We can write 70 as 70 + 1


Using Identity (a + b) 2 = a2 + 2ab + b2 for finding the value of


In the given expression a =


On substituting these values in the above identity, we get




(ii) We can write 100 as 100 - 1


Using Identity (a - b) 2 = a2 - 2ab + b2 for finding the value of


In the given expression a =


On substituting these values in the above identity, we get




(iii) We can write 102 as 100 + 2


Using Identity (a + b) 2 = a2 + 2ab + b2 for finding the value of


In the given expression a =


On substituting these values in the above identity, we get




(iv) We can write 998 as 1000 - 2


Using Identity (a - b) 2 = a2 - 2ab + b2 for finding the value of


In the given expression a =


On substituting these values in the above identity, we get




(v) We can write 5.2 as 5 + 0.2


Using Identity (a + b) 2 = a2 + 2ab + b2 for finding the value of


In the given expression a =


On substituting these values in the above identity, we get




(vi) 297× 303


We can write 297 as 300 – 3 and 303 as 300 + 3


Using Identity



In the given expression


On substituting these values in the above identity, we get


=


(vii) 78 × 82


We can write 78 as 80 – 2 and 82 as 80 + 2


Using Identity



In the given expression


On substituting these values in the above identity, we get


=


(viii) We can write 8.9 as 8 + 0.9


Using Identity (a + b) 2 = a2 + 2ab + b2 for finding the value of


In the given expression a =


On substituting these values in the above identity, we get




(ix) 1.05 × 9.5 = 1.05 × 0.95 × 10


We can write 1.05 as 1 + 0.05 and 0.95 × 10 as (1 – 0.05) × 10


Using Identity




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