Question

B(x)=7.4x^2-15x+4046 D(x)=-3.5x^2+20x+2405
B(x)=# of births D(x)=# of deaths

A. Write a function that models the total number of births and deaths in the United States for each year from 2000 through 2005.
B. Use the fuction from part (a) to find the total numer of virths and deaths in the United States in 2005.

Answer 1

does x represent the year in each of these functions?

Answer 2

I believe so, but that is also what I am questioning myself. I was able to reference a similar problem and figured out the answer for A. is (B+D)(x)=3.9x^2+35x+6451.
But I still can't figure out B.

Answer 3

D(x) looks like it will give a negative result. that may be fine as it represents the total number of deaths.

Answer 4

if that is so, then the total number of births and deaths should be:\[\begin{align}
Total=B(x)-D(x)&=7.4x^2-15x+4046-(-3.5x^2+20x+2405)\\
&=7.4x^2-15x+4046+3.5x^2-20x-2405\\
&=10.9x^2-35x+1641
\end{align}\]

Answer 5

then, to get the total for 2005, just work out the resulting expression for x=2005.

Answer 6

finally got it!! thank you!

Answer 7

yw

Answer 8

im still lost as to how to get x=2005 is it 5 but then how do i get the total number of b&d for 2005 HELP!!!