DQ/dP refers to how much demand will change if the price fluctuates a little, that is, the rate of change of demand relative to the price, and it can also be said that the degree of dependence of demand on the price, that is, the price elasticity of demand.

Qd= 14—3P，Qs=2+6P

14-3P=2+6P，P=4/3，Q= 10。

dQd/dP=-3，dQs/dP=6

The demand price elasticity is 3, and the supply price elasticity is 6.

Supply is more dependent on price. Price has a greater impact on supply.

Ps: I have never studied microeconomics, and I understand it purely from a mathematical point of view.