Question

solve by using identities: 12.1 square - 7.9 square

by full procedure.

Answer 1

Hi...☺

Here is your answer...✌

(12.1)² - (7.9)²

= (12+0.1)² - (8-0.1)²

= [12²+(0.1)²+2×12×0.1] - [8²+(0.1)²-2×8×0.1]

= (144+0.01+2.4) - (64+0.01-1.6)

= 146.41-62.41

= 84

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IDENTITY USED :

★ (a+b)² = a²+b²+2ab

★ (a-b)² = a²+b²-2ab

Answer 2

Answer:

84 is the answer please follow meeee....