Find the limit by rewriting the fraction first. 2x-2y lim (x,y)(1,-1) x+y Select the correct choice below and, if necessary, fill in the answer box to complete A. lim (x,y)(1,-1) 2x-2y2 x+y || OB. The limit does not exist. (Simplify your answer.) 2 2 Find an equation for the level surface of the function f(x,y,z) = x + y+z through the given point (6,-1,2). 2 An equation for the level surface is x + y + z (Simplify your answer.) = || < Find an equation for and sketch the graph of the level curve of the function f(x,y) that passes through the given point. f(x,y) = x + y+1, (4,2) What is the equation for the level curve? (Type an equation.) What is the graph of the level curve of f(x,y)? A. X B. Ay File Explorer X N C. 10 Ay X 10 D. 20 Ay 9 X 20