Answer:
C. x=15
Step-by-step explanation:
Use the Pythagorean Theorem:
[tex]a^{2} +b^{2} =c^{2}[/tex]
Plug in the known values:
[tex]9^2+12^2=c^2[/tex]
Simplify:
[tex]81+144=c^2[/tex]
Solve:
[tex]255=c^2[/tex]
[tex]\sqrt{225} =c^[/tex]
[tex]15=c[/tex]
