Given f x please help me set them up and stuff

Solve for n? [tex]z = \frac{3}{4} mn[/tex]

Answer! if you don’t mind, can you explain

Hassan bought a package of tofu. the temperature of the tofu was 14° celsius when hassan put the package into the freezer. he left the tofu in the freezer until it reached –19° celsius. which expressions explain how to find the change in temperature, in degrees celsius, of the package of tofu? select three that apply.