7 The equation of a curve is \(3 x ^ { 2 } + 4 x y + 3 y ^ { 2 } = 5\).
- Show that \(\frac { \mathrm { d } y } { \mathrm {~d} x } = - \frac { 3 x + 2 y } { 2 x + 3 y }\).
- Hence find the exact coordinates of the two points on the curve at which the tangent is parallel to \(y + 2 x = 0\).