80 because 160 divided by 2 is 80 so 2 x 80
Discussion
The discriminate is b^2 - 4*a*c
The general equation for a quadratic is ax^2 + bx + c
In this equation's case
a = 1
b= -5
c = - 3
Solve
(-5)^2 - 4*(1)*(-3)
25 - (-12)
25 + 12
37
Note
Since the discriminate is > 0, the roots are real and different. The roots do exist and there are 2 of them.
I'd say yes. If you use the diagonal as a reference. Take the square and set your compass to the width of the diameter of the square. Now put it on the page and mark a point. Put the point of the compass on that mark and make another mark. Now you can connect the two marks with the straight edge and you have a line that, if you made a square with sides that long, it'd have 2x the area of the first one. That's because the diagonal is the square root of 2 larger than one side. Square the square root of 2 and you've got 2. You lust need to make a perpendicular line to the first one to get the box going.