Assuming the parabola is in A^2+Bx+C=0, you can determine how many x-intercepts a function has by doing b^2-4ac. If it’s positive, there are two. If it’s 0, there is 1. If it’s negative, there are none.
(-6)^2-4(3)(5)
=36-60
=-24
Therefore there are 0 X-intercepts