differentiate the following to find the equation for the gradient of the curve in terms of x and y: 3x^3 + 4x^2 + 5xy + 7y = 0
9x^2 + 8x + 5y +5xdy/dx + 7dy/dx = 0
9x^2 + 8x + 5y = dy/dx(-5x - 7)
dy/dx = - (9x^2 + 8x +5y)/(5x + 7)
9x^2 + 8x + 5y +5xdy/dx + 7dy/dx = 0
9x^2 + 8x + 5y = dy/dx(-5x - 7)
dy/dx = - (9x^2 + 8x +5y)/(5x + 7)
