Could you help me with this question please? Thank you

In Exercises 53-58, determine the level surfaces c = -3, -2, -1, 0, 1, 2, 3 if they exist for the specified function. 53 f (x, y, 2) = x + 2y+3: 54. f (x, y, 2) = -2x -y+42 X x2+ 12 55. f (x, y, 2) = - 2 56. f (x, y, 2) = 57. f (x, y, 2 ) - x2 + 12+2- 58. f(x, y, =) = \\1 - (x2 + 12 +=?)