If Newton's Method is used to locate a root of the equation #f(x)=0# and the initial approximation is #x_1=2#, find the second approximation #x_2#?

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"Suppose that the tangent line to the curve #y=f(x)# at the point #(3,8)# has the equation #y=5-3x#. If Newton's Method is used to locate a root of the equation #f(x)=0# and the initial approximation is #x_1=2#, find the second approximation #x_2#?"

PLEASE APPLY CALCULUS I METHODS.
I have solved the equation with my own efforts, check my answer please?