Respuesta :

hey user


l think it is 

5

hope this helped

have a good day
you'd do 13^2 -12^2 as b^2 = c^2 - a^2 so
x^2 = 169(13^2) - 144 (12^2)
169 - 144 = 25
So square root 25 = 5
x = 5