J. . . EXERCISES = 7.2 a Exercises I through 20, compute all first-order amal derivatives of the given function. If(x, V) = 7x - 3y + 4 by(. )) = x- xy + 3 1 /(x. y) = 4x' - 3x y + 5.x 4 f(x. y) = 2x(y - 3x) - 4y Bill. y) = 215 + 3x-y + 12 A : = Sry + 2ry + 3x2