# Equation of the Tangent to the Curve

Calculus Level 2

Given that the equation of the tangent to the curve $$(y-2)^2=x,$$ which is parallel to the line $$x-2y=4,$$ can be expressed in the form $$Ax-By+C=0,$$ where $$A, B$$ and $$C$$ are coprime, positive integers, find the value of $$A-B+C.$$

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