Question

729-216-27
Evaluate using identity

Answer 1

Answer: 729-216-27= 486

Step-by-step explanation:

The identity for this question, we are going to use is given by:

a^3+b^3+c^3-3abc= (a+b+c)(a^2+b^2+c^2-ab-bc-ac)

729-216-27

We can write the above equation as follow:

9^3-6^3-3^3

Now, equating the above expression with the identity, we get:

a=9, b= -6, and c= -3

Here, a+b+c would be equal to 0, because 9+(-6)+(-3)=0

So, we get:

a^3+b^3+c^3= 3abc

Now, putting the value of a, b, and c in the above equation, we get:

9^3-6^3-3^3= 3*9*(-6)*(-3)

9^3-6^3-3^3= 486