Question

evaluate using identity : (85 square - 15 square)

Answer 1

Used Identity :- $a^{2} - b^{2} = (a+b)(a-b)$

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Now,

$(85^{2} - 15^{2} ) = (85+15)(85-15)$

                           = 100*70

                            = 7000



i hope this will help you



-by ABHAY

Answer 2

[ ( 85 )² - ( 15 )² ]

[ Using identity a² - b² = ( a + b ) ( a - b ) ]

( 85 + 15 ) ( 85 - 15 )

= 100 × 70

= 7000