Answer:
b. 12
Step-by-step explanation:
[tex] {h}^{2} = {x}^{2} + {y}^{2} \\ {x}^{2} = {h}^{2} - {y}^{2} \\ x = \sqrt{ {h}^{2} - {y}^{2} } \\ x = \sqrt{ {(15)}^{2} - {(9)}^{2} } \\ x = \sqrt{225 - 81} \\ x = \sqrt{144} \\ x = 12[/tex]
