[( 2a^-3) / b^2]^-4
=[2/(a³b²﹚]^-4
=[(a³b²﹚/2]^4
=a^12b^8/16
(-2.4× 10^-5)÷(6× 10^-3)
=(-2.4÷6)×[﹙10^-5)÷﹙10^-3)]
=-0.4×10^-2
=-0.004