Find the coefficient of x^3 in the expansion of (2x^2 - 3/x)^6

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Math it's appreciated. (picture provided)