1/2 f(-1,1)-2g(-3,3) when f(x,y)= x + 2y-3, g(x,y)=4xy-54/x^2+3y

Just plug in the numbers indicated for x and y and crank out the values of each function. Example: If x= -1 and y=1, corresponding to the (-1,1) point, then
f(x,y) = -1 + (2*1)-3 = -2
(-1/2)f(x,y) = -1

Similarly
g(-3,3) = (4*-3*3)-54/9 + 3*3
= -36 - 6 + 9 = -33
-2 g(-3,3) = 66
Now out it all together

(1/2)f(-1,1)- 2g(-3,3)= ____