This is in Differential Calculus. This is only multiple choice. Provide necessary solution for each items. Thank you and Godbless.

19. If x y -xtany +xe - 3 = 0, find - by partial differentiation. 2ry - tany te 2ry - tany +e A) C) x' - xsec y +xe' x - xsec y+xe x -xsec y +xe' x - xsec y+xe" B) D) 2xy -tany +e' 2ry - tany +e' 20. Use partial derivative to compute y in the equation x y +xy'-xly + y sinx -4 =0. x'yty' -xly +ycos.x 3x y+ y' - ly + y cos.x A) C) x' + 3xy? _ x - + sinx x'+ 3xy' - ly + sinx y x' + 3xy - + sinx 3x y+y' - ly +ycos.x y B) D) x3 + 3xy- - + sinx 3x y+y - ly +ycosx