Answer:
x = -6
Explanation:
We see that angles SPT and QPT are smaller parts of a larger angle (∠QPS).
The diagonals of rhombi bisect angles, meaning angles SPT and QPT are congruent and thus have the same measure.
Therefore, we can solve for x by setting the measures of the two angles equal to each other:
(50 = -10x - 10) + 10
(60 = -10x) / -10
-6 = x
Thus, x = -6.