1. Find the points on the graph of $\displaystyle z = x^2e^y$ at which the tangent plane is parallel to $\displaystyle 5x - 2y + \frac{1}2z = 0$

Can someone explain this to me/start this for me?

2. Suppose that the plane tangent to the surface $\displaystyle z = f(x,y)$ at $\displaystyle (-2,3,4)$ has equations $\displaystyle z + 4x + 2y = 2$. Estimate $\displaystyle f(-2.1, 3.1)$

Same as above; I'm not really sure where I'm supposed to start. Do I integrate $\displaystyle -(4x + 2y) + 2$ or something?