What are the major limitations of statistics​

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

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.

Me because i don't understand how to do it.: )