8=2y+2

∴y=3

The 3y power of 3 = the (x- 1) power of 3.

3y=x- 1

9=x- 1

∴x= 10

∴xy=30

2 、=x？ -x？ -x？ =-x？ Is it multiplication or subtraction in the middle?

=x？ ×x？ ×x？ =x to the seventh power

3 、=-a？ The (2n+ 1) power of -A and the 27th power of-a.

There is something wrong with your questions 2 and 3.