-2.5, -1.1, -4/5, 0.8, 9/5
Answer: 12.5
Step-by-step explanation:1.50*5=7.5
7.5-70=62.5
62.5 divided by 5 = 12.5
Given:
The volume of the rectangular prism is
![b^{3}+8 b^{2} +19b+12](https://tex.z-dn.net/?f=%20b%5E%7B3%7D%2B8%20b%5E%7B2%7D%20%2B19b%2B12%20)
,
the height is h=(b+3)
1. The volume of a rectangular prism is (base area)*height
also, notice that the volume is a third degree polynomial, the height is a 1st degree polynomial, so the base area must be a 2nd degree polynomial, whose coefficients we don't know yet.
Let this quadratic polynomial be
2
![b^{3}+8 b^{2} +19b+12=(mb^{2}+nb+k)*(b+3)](https://tex.z-dn.net/?f=b%5E%7B3%7D%2B8%20b%5E%7B2%7D%20%2B19b%2B12%3D%28mb%5E%7B2%7D%2Bnb%2Bk%29%2A%28b%2B3%29)
notice that
![b^{3}](https://tex.z-dn.net/?f=b%5E%7B3%7D)
is the product of the largest 2 terms:
![mb^{2}](https://tex.z-dn.net/?f=mb%5E%7B2%7D)
and b, so m must be 1
also, notice that 12 is the product of the constants, k and 3
so k*3=12, this means k=4
3
we write the above equality again:
![b^{3}+8 b^{2} +19b+12=(b^{2}+nb+4)*(b+3)](https://tex.z-dn.net/?f=%20b%5E%7B3%7D%2B8%20b%5E%7B2%7D%20%2B19b%2B12%3D%28b%5E%7B2%7D%2Bnb%2B4%29%2A%28b%2B3%29)
![(b^{2}+nb+4)(b+3)= b^{3}+3 b^{2} +nb^{2}+3nb+4b+12](https://tex.z-dn.net/?f=%28b%5E%7B2%7D%2Bnb%2B4%29%28b%2B3%29%3D%20b%5E%7B3%7D%2B3%20b%5E%7B2%7D%20%2Bnb%5E%7B2%7D%2B3nb%2B4b%2B12)
=
![= b^{3}+(n+3)b^{2}+(3n+4)b+12](https://tex.z-dn.net/?f=%3D%20b%5E%7B3%7D%2B%28n%2B3%29b%5E%7B2%7D%2B%283n%2B4%29b%2B12)
4
now compare the coefficient with the left side:
![8 b^{2}=(n+3)b^{2}](https://tex.z-dn.net/?f=8%20b%5E%7B2%7D%3D%28n%2B3%29b%5E%7B2%7D)
8=n+3
n=5
substituting n=5:
the base area is
![b^{2}+5b+4](https://tex.z-dn.net/?f=b%5E%7B2%7D%2B5b%2B4%20)
Answer:
6 1/12 - 4 2/3
6 1/12 - 4 8/12
5 13/12 - 4 8/12
1 5/12
The answer is 7!
The number In front of the variable is always the coefficient.