The closest i can think of that makes since is 1560=30(52)+b, mainly because
30 x 52 = 1560 so that's what i think it is and if im wrong sry.
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.
Difference is 2.71 and the estimate is 3
(3x^3+2x^2-5x) -(8x^3-2x^2)
-5x^3 -5x is the answer, there's not really any work to show, just subtract.