Question

Use property to evaluate $\left(6^3\right)+(-5^3)+(-1^3)$

• A. 90
• B. 80
• C. 70
• D. 100

Answer 1

The correct option is A

90

We know that if a + b + c = 0, then $a^3+b^3+c^3$ = 3abc

Here the components representing a,b, and c are 6,-5 and -1 respectively.

Hence a + b + c = 6 - 5 -1 = 0

Hence the first condition is satisfied.

So $\left(6^3\right)+(-5{)}^3+(-1{)}^3$ = 3(6 $\times$ (-5) $\times$(-1))

= 3 $\times$ 30

=90