An unevenly heated plate has temperature T(x,y) in degrees celcius at the point (x,y). If T(2,1)=135, and Tx(2,1)=16 and Ty(2,1)= -15, estimate the temperature at the point (2.04, 0.97).
Where exactly are you stuck?
Just substitute into the usual formula. To wit:
$\displaystyle T(x + \delta x, y + \delta y) \approx T(x, y) + T_x (x, y) \, \delta x + T_y (x, y) \, \delta y$.
Note that x = 2, y = 1, $\displaystyle \delta x = 0.04$ and $\displaystyle \delta y = -0.03$.