Answer:
- 4
Explanation:
Using the rule of exponents
•
×
⇔

•
⇔

=
=

and right side
=
×

Hence
=
×

=

Equating exponents on both sides gives
a + 10 = - 2a - 2 ( add 2a to both sides )
3a + 10 = - 2 (subtract 10 from both sides )
3a = - 12 ( divide both sides by 3 )
a = - 4