1) No, because the line does not divide the figure into two mirrored images.
2)Yes, because the line divides the figure into two mirrored images.
3) Yes, because the line divides the figure into two mirrored images.
4)No, because the line does not divide the figure into two mirrored images.
5)One line, vertical down the middle.
6) Zero lines, because the figure can not be divided into mirrored images.
7)Four lines, horizontal down the middle, vertical down the middle and diagonal down from each top corner.
8) One line, vertical down the middle
Answer
Square prism
It has 2 squares and 4 rectangles
Start with expression 
1. Separate terms - with x leave in left side, without x write in right side:

2. Divide the last expression by a (
):

Answer: this statement is true when
.