You answered your own question?
Power
103 x
An exponent.
You can but it has no particular significance.
No.
You answered your own question?
negative 8 would be the base and the 15 would be the exponent
5de
Most likely it is a logarithm.
Power
103 x
In the expression 45 the 4 is the base and the 5 is the exponent.
Then, if the exponent is a positive integer, the value is 1 multiplied by the base repeatedly, exponent times. If the exponent is a negative integer then it is the reciprocal of the above value.In either case, it is NOT the base multiplied by itself an exponent number of times.
An exponent.
In the expression 43, 4 is the base and 3 is the exponent.
7n^5