when solved graphically, which system of equations will have exactly one point of intersection and why?

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

In 2009, there were 1570 bears in a wildlife refuge. in 2010, the population had increased to approximately 1884 bears. if this trend continues and the bear population is increasing exponentially, how many bears will there be in 2018?

About 9% of th population is hopelessly romantic. if 2 people are randomly selected from the population, what is the probability that at least 1 person is hopelessly romantic?