find dydx of

x^2 + 3xy + 2y^2 = 5

My working

2y^2 = 5 - x^2 - 3xy

y^2 = 1/2 . (5 - x^2 - 3xy)

y = root 1/2 . (5 - x^2 - 3xy)

y = 1/2 . (5 - x^2 - 3xy)^1/2

y = (2.5 - 1/2x^2 - 1.5xy)^1/2

y1 = 1/2 (2.5 - 1/2x^2 - 1.5xy)^-1/2. 3

Advice please if i am close

Cheers