please help me with these questions

Step-by-step explanation:
you don't know how exponents work ?
the exponent simply says how often the base value has to be multiplied by itself.
e.g. 5³ = 5×5×5 = 125
and when it says x=2, then you need to put 2 at every location, where is says "x".
so,
x⁵ for x = 2 means 2⁵ = 32
8² = 64
2⁴ = 16