25^-1+3(5^-1)^2

(4+8)^0-5^-2

(-1/2)^3+4^-3

(-3)^-1+4^0-6^-1

1. 25^-1 + 3(5^-1)^2 =

1/25 + 3(1/5)^2 =
1/25 + 3(1/25) =
1/25 + 3/25 = 4/25.

2. (4+8)^0 - 5^-2 =
(12)^0 - 1/5^2 =
1 - 1/25 =
25/25 - 1/25 = 24/25.

3. (-1/2)^3 + 4^-3 =
-1/8 + 1/4^3 =
-1/8 + 1/64 =
-8/64 + 1/64 = -7/64.

4. (-3y)^-1 + 4^0 - 6^-1 =
-1/3y + 1 - 1/6 =
-1/3y + 6/6 - 1/6 =
-1/3y + 5/6.