I would appreciate help about this :D

You can't have cosine of an angle greater than 1.  Did you mean cos Z = 5/7?

i mean 7 / 25 sorry

In XYZ, and X = 90° , and cos Z = 7/ 25. Find sin Z and tan Y.

cos(Z) = 0.28

sin(Z) = 0.96

tan(Y) = 0.2916666666666666