Good Afternoon,
Okay so we have 15 hours already, now we need to add 60 minutes, which is exactly an hour.
So, 15 Hours + 1 Hour = 16 Hours.
16 Hours is your answer, I hope I helped and good luck studying!
Thank you,
Darian D.
From the problem :

In multiplying expressions with the same bases, the exponent will be added accordingly.
For example :

the exponent of a are m and n, and the product will be a raised to the sum of m and n.
Applying this to the problem, we have :

The answer is d. 6^-1
128 square inches of wrapping paper, since the width would be the Z Axis, That would make a Square 3X4= 12, 12X2= 24. 3X7= 21X4= 104, 104+24=128? That's what I figured. Can you send me a photo of the problem?
They definitely can be positive they can be negative and they can have an absolute value but I would choose they both can be positive and negative