Answer:
After 4 days, the number of people attending both conferences be the same.
Step-by-step explanation:
We are given the following in the question:
Maths conference:
Number of people already signed = 7
Number of people who sign up each day = 2
Thus, the number of people who will sign up for maths conference in x days will be given by the linear function:
![f(x) = 7+2x](https://tex.z-dn.net/?f=f%28x%29%20%3D%207%2B2x)
History conference:
Number of people already signed =11
Number of people who sign up each day = 1
Thus, the number of people who will sign up for maths conference in x days will be given by the linear function:
![g(x) =11+x](https://tex.z-dn.net/?f=g%28x%29%20%3D11%2Bx)
Both conference will have same number of people when
![f(x) = g(x)\\\Rightarrow 7 + 2x = 11+x\\\Rightarrow x = 4](https://tex.z-dn.net/?f=f%28x%29%20%3D%20g%28x%29%5C%5C%5CRightarrow%207%20%2B%202x%20%3D%2011%2Bx%5C%5C%5CRightarrow%20x%20%3D%204)
Thus, after 4 days, the number of people attending both conferences be the same.