Answer:
can you not just divide by 2 because you want to serve half the people?
Step-by-step explanation:
An open shape is made up of line segments. In this type of shape there is at least one line segment that is not connected to anything at one of its endpoints, so the shape is not a closed figure. So, I am going to provide four graphs for this problem.
1. Parable
This is given by the curve:

See figure 1.
2. Cubic function.
This function is given by:

see figure 2
3. Quartic function
This curve is given by:

see figure 3
4. Cosine functionThis function is given by this equation:

See figure 4.
All these curves are open shapes. So, we can find a new open shape as the sum of all these curves as follows:

See figure 5.
<span>when the graph touches x axis at that point y = 0
</span><span> So, putting y =0
0 = -3x^2 + x +4
</span>so, if you factoriazte it
<span>−3<span>x^2</span>++4x−3x+4=0
</span>
<span>−3x(x+1)+4(x+1)=0
</span>
<span>(x+1)+(−3x+4)=0
</span>
<span><span>x=−1,<span>4/3
So, two time at -1 and 4/3 it touches the x-axid</span></span></span>
The answer is $6,000, because you multiply the 25,000 times .6 percent for interest, then multiply $15000 times .4 years and $6000 will be what you pay in interest.