Consider the family of curves described by: x^2+ xy + ay^2= b. Remember to justify your answers. A. Let a =1 and b = 7. Find the two x-intercepts.
B. Let a =1 and b = 7. Using the two points you found in part A, show that the tangents to the curve at these points are parallel, and find the common slope.
C. A given curve in the family x^2 + xy + ay^2 = b has a tangent line at point (1, 3) with slope −5/14. What are the values of a and b?

I need help with part a and part b. I don't understand them.