She will use 3 rows of 3 squares, for a total of 9 squares.
Since the shape she is covering is a square, all of the sides are equal. If 3 square tiles fit across the width of the top, then 3 square tiles fit across the length of it as well. This makes 3 by 3, or 9 squares.
10=a/2 + 7
First subtract 7 from both sides
3=a/2
Next multiple 2 on both sides, so that a is by itself
3(2)=a
A=6
4.2^n+12^n+2/2^n+12^n
Step-by-step explanation: