Finding the dy/dx at the point (-2, 1)

26. If x^2 + 3xy - y = 11, the dy/dx at the point (-2, 1)

a. -1
b. -2
c. 1
d. - 1/7
e. 2

Implicit Differentiation:

x² + 3xy - y = 11
2x + 3xy' + 3y - y' = 0
2x+3y + (3x-1)y' = 0
y'(x,y) = (2x+3y)/(1-3x)
y'(-2,1) = (-4+3)/(1+6) = -1/7

d. is the correct choice

implicit differentiate and plug the point in