what do you do with the exponent when the base are different?

Question

for example : 8^-2 - 2x^0

Answer 1

You need to know the rules first regarding exponents.

A negative exponent such as x^-2 is the same as saying 1/x^2. Another example would be 3X^-3 is the same as writing 1/3X^3.

The rule that applies for the second part is that any number with an exponent of 0 always = 1. For example 888^0 = 1.

So solving the above equation = 1/8^2 - 2 x 1
this breaks down to 1/64 -2 = 1/64 - 128/64 = -127/64

Answer 2

8^-2 - 2x^0 = 1/8*8 - 2*1 = 1/64 - 2 = - 1 63/64