1. The problem statement, all variables and given/known data Find all points on the curve x^2 * y^2 + xy = 2 where the slope of the tangent line is -1. 2. Relevant equations y' = -1 3. The attempt at a solution I got the y' = [ -2xy^2 - y ] / [ 2x^(2)y + x ] to be the gradient which I am sure is right. Then I subbed in y' = -1 and tried to solve for y, where I reached the line -2x^(2)y + 2xy^(2) + y = x. Is there a way to factor out the y?