For future reference, here is how to solve negative exponents.
For example
3^-4
take the reciprocal of 3 (write 3 as a fraction, 3/1, and write it the other way, 1/3). Then, raise 1/3 to the power of whatever the original exponent was, minus the negative, 4.
So
3^-4 = (1/3)^4 = 1/81 or 0.012345678901234567890123...