u^2 - 3 uv + v^2 = (u^2 + 2 uv + v^2) - 2 uv - 3 uv = (u+v)^2 - 5 uv
1/u^2 + 1/v^2 = (u^2+v^2)/(u^2*v^2)= ((u^2+2uv+v^2)-2uv)/(uv)^2 = ((u+v)^2-2uv)/(uv)^2
u^2 - 3 uv + v^2 = (u^2 + 2 uv + v^2) - 2 uv - 3 uv = (u+v)^2 - 5 uv
1/u^2 + 1/v^2 = (u^2+v^2)/(u^2*v^2)= ((u^2+2uv+v^2)-2uv)/(uv)^2 = ((u+v)^2-2uv)/(uv)^2