In this position, you might consider exchanging, seeing that OX has two spots at 8c and 1c that can score lucratively.  However, by noticing the 8 As in the bag, you can find that OX 7b immediately is better, as those remaining A tiles allow you to play EUOUAE in two spots: 1a, and b10, both for nearly 40 points.  Although it’s usually worth keeping the X in these sorts of positions because of propensity, the presence of EUOUAE makes offloading the X now a better option.