Answer:
(I don't know if this is correct)
To find the length of the rectangle, you need to first do 20 x 2 = 40 because when you finding the perimeter you have to do W + L + W + L = P (or Wx2 + Lx2 = P). You then subtract 40 from 68 (68 - 40) where you get 28 left. you then just divide 28/2 and you get 14. I may be way off but that's how I learned it.
Our polynomial is
We can tell from -28 that the binomials are one positive and one negative.
We can use a factoring chart. What adds to make +3x and multiplies to make -28.
To get a negative 28, we can multiply -4 and positive seven, which add together after being multiplied by x to get +3x. Therefore, you are left with (x+7) and (x-4).
The pyramid has 4 faces. Each face is a triangle with a base of 12 and a height of 7. The area of any triangle is half of the product (base)x(height). If you also want to include the area of the pyramid's base, that's a square with sides of 12, and the area of a square is the square of the length of a side.
Characteristic equation:
Given that
and
, you have
so that the particular solution is