If you answer this i will give you brainliest!! 21pts
jenna's band is going to record a cd at a recording studio. They will pay $225 to use the studio for one day and $80 per hour for sound technicians. Jenna has $200 and can reasonable expect to raise an additional $350 by selling pre-orders for the cd.
a)explain how the inequality 200 < 225 + 80x < 550 can be used to find the number of hours jenna and her band can afford to use the studio and sound technicians.
b)solve the inequality. Are there any numbers in the solution set that to the situation?
c)suppose jenna raises $350 in pre orders. How much more money would she need to raise if she wanted to use the studio and sound technicians for 6 hours?

Respuesta :

A

Let x be the number of hour spent in the studio. Since 225 is a fixed price, and they pay 80 dollars per hour, the total cost will be [tex] 225+80x [/tex]. Jenna has 200 dollars, and can raise 350 more dollars, so she can spend any amount between 200 and 200+350=550. That's why the inequality models this problem.

B

To solve the inequality, subtract 225 to all sides:

[tex] 200 - 225 < 225 + 80x < 550 - 225 \iff -25 < 80x < 325 [/tex]

Divide all sides by 8:

[tex] -\dfrac{25}{80} < x < \dfrac{325}{80} [/tex]

A negative value for x doesn't actually make sense, so the solution space is

[tex] 0 < x < \dfrac{325}{80} = 4.0625[/tex]

So, she can rent the studio for up to 4 hours.

C

The price for 6 hours is

[tex] 225+80\cdot 6 = 705 [/tex]

If Jenna raises 350 dollars, she has 550 dollars. So, she needs

[tex] 705-550 = 155 [/tex]

more dollars to rent the studio for 6 hours