please help immediately

Answer: [tex]f'(1)=\dfrac{4}{2y+1}[/tex]
Step-by-step explanation:
To find the tangent, you need to find the derivative with respect to x.
Then substitute x = 1 into the derivative.
Given: 0 = 2x² - xy - y²
Derivative: 0 = 4x - y' - 2yy'
Solve for y': 2yy' + y' = 4x
y'(2y + 1) = 4x
[tex]y'=\dfrac{4x}{2y+1}[/tex]
[tex]\text{Substitute x = 1:}\quad y'(1)=\dfrac{4}{2y+1}[/tex]