Find kkk such that the function f(x)=2x+3x−kf(x) = \frac{2x+3}{x-k}f(x)=x−k2x+3 has a vertical asymptote at x=4x=4x=4.
k=4k=4k=4
k=−4k=-4k=−4
k=2k=2k=2
k=3k=3k=3