A laser’s beam shines along the ray given by r₁(t) = (1, 2, 4) + t(2, 1, −1) for t ≥ 0. A second laser’s beam shines along the ray given by r₂(s) = (6, 3, −1) +  s(−5, 2, c) for s ≥ 0, where the value of c allows for the adjustment of the z-coordinate of its direction vector. Find the value of c that will make the two beams intersect.