Answer:
![y=1.25x+3.5](https://tex.z-dn.net/?f=y%3D1.25x%2B3.5)
Step-by-step explanation:
Given:
The relation between the number of tickets and total cost for purchasing them.
Let
represent number of tickets and
represent the total cost to purchase them.
Now, let the relation be given by the following function:
, where,
and
are constants.
Let us find
and
using the values from the table.
For,
. So,
![12.25=7m+b\\or\ 7m+b=12.25------------1](https://tex.z-dn.net/?f=12.25%3D7m%2Bb%5C%5Cor%5C%207m%2Bb%3D12.25------------1)
For,
. So,
![16=10m+b\\or\ 10m+b=16------------2](https://tex.z-dn.net/?f=16%3D10m%2Bb%5C%5Cor%5C%2010m%2Bb%3D16------------2)
Subtract equation 1 from equation 2. This gives,
![10m+b-7m-b=16-12.25\\(10m-7m)+(b-b)=3.75\\3m=3.75\\m=\frac{3.75}{3}=1.25](https://tex.z-dn.net/?f=10m%2Bb-7m-b%3D16-12.25%5C%5C%2810m-7m%29%2B%28b-b%29%3D3.75%5C%5C3m%3D3.75%5C%5Cm%3D%5Cfrac%7B3.75%7D%7B3%7D%3D1.25)
Now, plug in
in equation 1 and solve for
.
![7(1.25)+b=12.25\\8.75+b=12.25\\b=12.25-8.75=3.5](https://tex.z-dn.net/?f=7%281.25%29%2Bb%3D12.25%5C%5C8.75%2Bb%3D12.25%5C%5Cb%3D12.25-8.75%3D3.5)
Therefore, the function to represent the relationship between the tickets and total cost is given as:
![y=mx+b\\y=1.25x+3.5](https://tex.z-dn.net/?f=y%3Dmx%2Bb%5C%5Cy%3D1.25x%2B3.5)
I think it is the third one. If it’s not the third one then it’s the first one.
A is the correct answer I hope that helps :)
Her present age would be 5 because 4m=m+5 which would then turn into 3m=15 because you would subtract the m from both sides and end up with 3m+15, then you would divide 3 to both sides which would then give u an answer of m=5