Answer:

Explanation:
[ Step One ] Remove Parenthesis: (a) = a

[ Step Two ] Multiply: 

[ Step Three ] Apply Exponent Rule 

[ Step Four ] Apply Exponent Rule: 

[
]
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Those number are all powers of 10
10= 10^1
100= 10^2
1000= 10^3
and so on...
Answer:
-8
Step-by-step explanation:
1/2 times 10 is 5. and a negative times a negative is a positive, so you have a positive 12, which becomes 5+12-25, which is -8