1. The problem statement, all variables and given/known data Suppose that z is a linear function of x and y with slope -1 in the x direction and slope 4 in the y direction. Part a) A change of −0.1 in x and 0.3 in y produces what change in z? z = ? Part b) If z=5 when x=7 and y=6, what is the value of z when x=7.1 and y=5.7? z = ? 2. Relevant equations 3. The attempt at a solution I really do not know where to start with this problem. Maybe setting a system of equations and solving for z? What does the "with slope -1 in the x direction and slope of 4 in the y direction" mean? Any help to start this problem with help me thank you.