110 find dydx by differentiating implicitly then find the va

1-10 find dy/dx by differentiating implicitly then find the value of dy/dx at the

a) 2x + 2y(dy/dx) = 0

dy/dx = -x/y

at (6,8) dy/dx = -6/8 = -3/4

b) 2x - 3y - 3x(dy/dx) + 7dy/dx = 0

dy/dx = (2x -3y)/(3x-7)

at (2,1) , dy/dx = -1

c) 2x/9 + (2y/16)dy/dx = 0

dy/dx = -16x/9y

at (0,4) dy/dx = 0