I need help with a math problem

I need help with a math problem

1.

(17)^3.5 x (17)^? = 17⁸

2.

Given that 10^0.48 = x, 10^0.70 = y and x^z = y², then the value of z is close to:

3.

If 5^a = 3125, then the value of 5^{(a – 3)} is:

4.

If 3^{(x – y)} = 27 and 3^{(x + y)} = 243, then x is equal to: 

6.

(256)^0.16 x (256)^0.09 = ?