Answer:
The company needs to sell either 30 or 40 items.
Step-by-step explanation:
We are given that the cost for selling x items given by the function:
[tex]C(x)=40x+180[/tex]
And the revenue for selling x items is given by:
[tex]R(x)=68x-0.4x^2[/tex]
The profit function is the cost function subtracted from the revenue function:
[tex]P(x)=R(x)-C(x)[/tex]
Substitute and simplify:
[tex]\displaystyle \begin{aligned} P(x)&=(68x-0.4x^2)-(40x+180)\\&=68x-0.4x^2-40x-180\\&=-0.4x^2+28x-180\end{aligned}[/tex]
To find how many items must be sold in order to obtain a weekly profit of $300, we can let P equal 300 and solve for x. So:
[tex]300=-0.4x^2+28x-180[/tex]
Solve for x. Subtract 300 from both sides:
[tex]-0.4x^2+28x-480=0[/tex]
We can divide both sides by -0.4:
[tex]x^2-70x+1200=0[/tex]
Factor:
[tex](x-40)(x-30)=0[/tex]
Zero Product Property:
[tex]x-40=0\text{ or } x-30=0[/tex]
Solve for each case:
[tex]x=40\text{ or } x=30[/tex]
So, in order to obtain a weekly profit of $300, the company need to sell either 30 or 40 items.
