30,000 how many thousands are in the answer

Given δjkl : δxyz, find x. a)10 b)12 c)16 d)20

Shape a is congruent to shape , as shown by a reflection across the y-axis and then a translation down units. shape b is congruent to shape , as shown by a reflection across the y-axis and then a translation down units.

Determine if this is a solution to the system