if sec(x) = - squaroot 20 /3

(squroot applies to 20 not the fraction)

then state the exact vale of tan (x)

draw your triangle.

secθ = r/x and x<0, so θ is in QII or QIII

x = -3
r = √20
y = ±√11

Now just recall that tanθ = y/x, so it will be ±√11/3, depending on the quadrant.