In Problems 1-2, eliminate the cross-product term by a suitable rotation of axes and then, if necessary,

Question:

In Problems 1-2, eliminate the cross-product term by a suitable rotation of axes and then, if necessary, translate axes (complete the squares) to put the equation in standard form, Finally, graph the equation showing the rotated axes.
a. x2 + xy + y2 = 6
b. 3x2 + 10xy + 3y2 + 10 = 0