26. Match the functions (a)-(f) with the level curves (I)- (VI): (a) f(x, y) = x2 - y - 2x + 4y-3 (b) g(x. y) = x3 + 1 - 2x - 4y +15 (c) h(x, y) = -x3 - y + 2x +4y - 8 (d) j(x, y) =-x-+y +2x-4y+3 (e) k(x. y) = v(x - 1)2 + (y - 2)2 (f) I(x, y) = -V(x-1)2 + (y-2)2 0.5 1.5 X X Y (IV) y 0 -2 X X (V) (VI) 0.5 1.5 -2- X X