Question

evaluate the above by using identity

Answer 1

Hello Mate!

( 9.9 )^3 can be written as ( 9 + 0.9 )^3

We know that ( a + b )^3

${a}^{3} + {b}^{3} + 3 {a}^{2}b + 3a {b}^{2}$

Here, a = 9 and b = 0.9

9^3 + 0.9^3 + ( 3 × 9 × 0.9^2 ) + ( 3 × 9^2 × 0.9 )

729 + 0.729 + 21.87 + 218.7

970.299

Hope it helps☺!✌

Answer 2

SOLUTION :-
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$(9.9)^{3} = (10 - .1)^{3} \\ 1000 - 0.001 - 3 \times 10 \times .1(10 - .1) \\ = 999.999 - 3 \times 9.9 \\ = 999.999 - 29.7 \\ =( 970.299)ans \\ i \: hope \: it \: is \: helpfull \: for \: u$