Question

Simplify using associative property:

$(-5)\times \left[\right(-8)\times 2]=$ $....$

• A. $40$
• B. $-80$
• C. $80$
• D. $-40$

Answer 1

The correct option is C $80$

$(-5)\times \left[\right(-8)\times 2]=(-5)\times (2\times (-8\left)\right)$ (commutative property)
$=\left[\right(-5)\times 2]\times (-8)$ (associative property)
$=(-10)\times (-8)$
$=80$
(Here, we used various properties to skip $(-5)\times (-8)$ which could have been time consuming).