find equation of a tangent if f(x)=x^3+x^2+15x that passes at x=-3

If f(x)=y,dy/dx=3x^2+2x+15. At x=-3,dy/dx=36=m.at x=-3,y=-63.

So equation is: y-(-63)=36(x-(-3)) as y-y1=m(x-x1)

y=36x+45