Hey! I need someone to help me with this.

1)
Expression: (a-5)2
Simplified: ?

2)
Expression: a-9 x a17a7
Simplified: ?

3)
Expression: a-4a-7
Simplified: ?

4)
Expression: (a3)-2 x a2a3
Simplified: ?

5)
Expression: a22(a3)8
Simplified: ?

6)
Expression: a0x (a2)6
Simplified: ?

7)
Expression: (a5)3
Simplified: ?

8)
Expression: a-4x a15
Simplified: ?