Respuesta :

√z = 13 - 8
√z = 5
z = 5²
z = 25
In this case the z can be any number, however z cannot be less than 0 and that is the restriction. (for example; √-1 = irrational number, cannot be solved.)

I found this on the internet I hope it helps

√z = 13 - 8
√z = 5
z = 5²
z = 25

its on the answer key xD