Differentiating the equation of the curve with respect to x, we get
dydx=2x−2
Slope of the line 5y−15x=13 is 3.
Since the tangent is perpendicular to the above line,
dydx×3=−1
⇒dydx=−13
Using in the first equation, we get −13=2x−2
⇒x=56
Substituting the value of x in the equation of the curve, we get
y=(56)2−2(56)+7
⇒y=21736
Hence, equation of the tangent is
y−21736=−13(x−56)
⇒36y−217=−2(6x−5)
⇒12x+36y−227=0