1.
(17)3.5 x (17)? = 178

2.
$$\eqalign{ & {\text{If}}\,{\left( {\frac{a}{b}} \right)^{x - 1}} = {\left( {\frac{b}{a}} \right)^{x - 3}}, \cr & {\text{then}}\,{\text{the}}\,{\text{value}}\,{\text{of}}\,x\,{\text{is}} \cr} $$

3.
Given that 100.48 = x, 100.70 = y and xz = y2, then the value of z is close to:

4.
If 5a = 3125, then the value of 5(a - 3) is:

5.
If 3(x - y) = 27 and 3(x + y) = 243, then x is equal to: