Really stuck on the last three questions on my worksheet. Due in two hours could really use some help. Thanks!

5. Let f(x, y) = 3x414 _ 2x3yo. Find the rate of change in f(x,y) at the point (2,1) in the direction of v = 24. 7 25 25 (9 points) 6. Let f(x, y, z) = 1x2423 _2x3yz2. Find the rate of change in f(x,y,z) at the point (3, 1, 2) in the direction of v = =i - sit-k. (9 points) 7. Find the tangent plane to f(x, y) = e(8xy - 16) - 2xy - 2x2y + 4x + 8y at (1, 2, f(1, 2))). (12 points) Common so