Answer:
The product of 31 and x is 31x.
* eq 1 by 4 and eq 2 by 3 and add
24x-12y=60
21x+12y=30
45x=90
x=2
y=-1
X^2+10x+25 =8
Answer shown in figures below
We know that the area of any circle is Ac = πr**2The area of the square is As = l**2
If we substract the Areas, we can know the difference between them
d = πr**2 - l**2