a)
[tex]x {}^{2} - 4[/tex]
b)
[tex]a {}^{2} - 9[/tex]
c)
[tex]25 - x {}^{2} [/tex]
d)
[tex]16a {}^{2} - 4c {}^{2} [/tex]
e) la acest subpunct , probabil este gresit ceva
f)
[tex]2y { }^{2} - 25x {}^{2} [/tex]
g)
[tex]m {}^{2} - 9n {}^{2} [/tex]
h)
[tex]t {}^{2} - 4z {}^{2} [/tex]
i)
[tex]144a {}^{2} - x {}^{2} [/tex]