Question

Find the value of 9³ - 8³??​

Answer 1

To find : $9^{3} - 8^{3}$

Solution :

• To find the value of  $9^{3} - 8^{3}$  we apply identity : $a^{3} - b^{3} = ( a - b) ( a^{2} + ab + b^{2} )$
• Here, $a = 9$ and $b = 8$

• Therefore ,  $9^{3} - 8^{3} = ( 9 - 8) ( (9)^{2} + (9)(8) + (8)^{2})$

                                        $= (1) ( 81 + 72 + 64 )\\= 217$  

Hence, the value of  $9^{3} - 8^{3}$  is $217$.

                                       

Answer 2

• As per the data given in the question, we have to find the value of the expression.

          Given data:- $9^{3} -8^{3} .$

         To find:- Value of the expression.

         Solution:-

• We know the identity,

     $a^{3}-b^{3}=(a-b)\left(a^{2}+a b+b^{2}\right).$

             Here

                 $a=9\\b=8$

 $\begin{aligned}9^{3}-8^{3} &=(9-8)\left((9)^{2}+(9)(8)+(8)^{2}\right) \\&=(1)(81+72+64) \\&=217\end{aligned}$

   Hence we will get the value $217.$