y + 8xy = x^9 + 9x dy/dx + 8x(dy/dx) + 8y = 9x^8 + 9 dy/dx(1+8x) = 9x^8 + 9 - 8y dy/dx = (9x^8 + 9 - 8y)/(1+8x) plug in your point and you are done.
You can ask a new question or answer this question.