Please help

. Question 1 > Find the tangent plane to the equation z = - x + 2y - 4y at the point (4, - 5, 54). Question 4 Find the linear approximation to the equation f(x, y) = 4,/ cy 2 at the point (4,2,8), and use it to approximate f(4.28, 2.24) f(4.28, 2.24)~ Make sure your answer is accurate to at least three decimal places, or give an exact answer.A contour map for a function f is shown. 16 12 20 5 -4 -3 -2 401 Use the contour map to estimate the value of f, ( - 4, 2) fx( - 4, 2)~