Question

Using suitable identity, evaluate-:(i) (104)^3 (ii) (97)^3

Answer 1

Used identity : (a + b)³ = a³+b³+3ab(a + b)




( 104)³

=> ( 100 + 4)³

=> ( 100 )³ + ( 4 )³ + 3(100 + 4)(100 × 4)


=> (1000000)+(64)+312(400)

=> 1000064 + 124800


=> 1124864



(ii) :


(97)³


=> (90 + 7)³

=> (90)³ + (7)³ + 3(90+7)(90×7)

=> 729000 + 343 + 291(630)

=> 729343+183330

=> 912673

Answer 2

${ Hey Dear }$

Here is your answer

( 104 )³

(100 + 4 )³

identity = (a + b)³ = a³ + b³ + 3ab ( a + b)

so

( 100 + 4 )³ = (100)³ + ( 4)³ + 3 *(100)(4) ( 100 +4)

( 10²)³ + 64 + 1200 ( 104)

1000000 + 64 + 124800

= 1124864

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2) ( 97)³

( 100 - 3)³

identity = (a - b) ³ = a³ - b³ -3ab ( a - b)

( 100)³ - ( 3)³ -3 * (100)(3) ( 100 -3)

1000000 - 27 - 900( 97)

= 912673

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hope it helps

thank you