2a^2(a^-3)^4/(a^-2)^-3
Remember that a negative exponent means it is on the wrong part of the fraction. The (a^-3) must go to the denominator, and the (a^-2)^-3 needs to go to the numerorator.
2a^2(a^2)^3 / (a^3)^4 =
2 a^2(a^6) / a^12 =
2 a^8 / a^12
2 / a^4