Find a trinomial A(x) that represents the area of a parallelogram whose base is 3x + 2 meters and whose height is 2x + 3 meters. Find A(3).
This is what I got:
(3x+2)(2x+3)=
6x^2+9x+4x+6=
6x^2+13x+6 Is this right?
your statement should have been preceded by A(x) like this
A(x) = (3x+2)(2x+3)
then A(3) = (11)(9) = 99
It really doesn't matter whether you expand your expression or leave it in factored form.
In this case I was able to do the arithmetic mentally, had I used the expanded form I would have had to remember 4 different numbers then add them.
Reiny,
So since it is asking for A(x) and the x is what I wrote in parenthese I can leave it as A(x)= (3x+2)(2x+3).
If I wanted to solve, how did you get the (11)(9)? Wouldn't you do the FOIL method which would be:
6x^2+4x+9x+4=
6x^2+13x+4
I gues I got lost somewhere.
Yes, your calculations are correct. The trinomial A(x) that represents the area of the parallelogram is 6x^2 + 13x + 6.
To find A(3), we need to substitute x = 3 into the trinomial and evaluate it.
A(3) = 6(3)^2 + 13(3) + 6
= 6(9) + 39 + 6
= 54 + 39 + 6
= 99 + 6
= 105
So, A(3) = 105.