The producer of a rock concert has a limited number of tickets left to sell in in each ticket category. There are as many platinum tickets availableas gold tickets. The total number of silver and gold tickets available is 13. There are 13 more diamond tickets available than gold tickets. Thepeople managing ticket sales know that there are at least 3,600 possible combinations in which these tickets can be sold. Which statementsabout the situation are true?

Respuesta :

First, I will give the tickets the following names

Platinum tickets → P

Gold tickets → X

Silver tickets → S

Diamond tickets → D

You have this given information:

[tex]\begin{gathered} P=X \\ S+X=13 \\ D=X+13 \\ P\cdot X\cdot S\cdot D=3600 \end{gathered}[/tex]

The last one is for the possible combinations of the independent variables

Now, you need to let the last equation just with x variable, so you have to replace the other variables as

[tex]\begin{gathered} P=X \\ S=13-X \\ D=13+X \end{gathered}[/tex]

And then you will have the next equation

[tex]X\cdot X\cdot(13-X)\cdot(13+X)=3600[/tex]

If you take a look (13-X)(13+X)=13²-X², replacing again

[tex]\begin{gathered} X^2\cdot(13^2-X^2)=3600 \\ X^2\cdot(169-X^2)=3600 \\ -X^4+169X^2=3600 \end{gathered}[/tex]

At this point you will have to find the possible solutions for this equation

[tex]-X^4+169X^2-3600=0[/tex]

You can substitute t for x²

[tex]-t^2+169t-3600=0[/tex]

All equations of the form ax2+bx+c=0 can be solved using the quadratic formula:

[tex]t=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}[/tex]

If you replace a=-1, b=169 and c=-3600, then

[tex]\begin{gathered} t=\frac{-169\pm\sqrt[]{169^2-4(-1)(-3600)}}{2(-1)} \\ t=\frac{-169\pm119}{-2} \\ t=\frac{-169+119}{-2}=25\text{ and }t=\frac{-169-119}{-2}=144 \end{gathered}[/tex]

Since t=x², then

[tex]\begin{gathered} X=\sqrt[]{t} \\ X=\sqrt[]{25}=5\text{ and }X=\sqrt[]{144}=12 \end{gathered}[/tex]

Now the possible solutions for X are X=5 and X=12, and now you can evaluate the statements

For the first one, S=13-X, if X is 5 then S will be 8, and if X is 12 then S will be 1, so the first statement is false

The second one will be true because of the previous calculations we made

For the next 3 statements you can check the equation we use for the calculation of the gold tickets, as you can see, the one that matches is the third statement, this will be true. The other ones will be false then.

The answer will be: The second and the third statement are true

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