Sara wants to find the input value that produces the same output for the functions represented by the tables.

what is the input value that produces the same output value in both charts?

Unfortunately, there are no given tables. To solve the given problem, the functions which fits the values in the tables must be known. This process is called modeling. One could test if the values fit a linear model, a quadratic model, or any other model. After knowing the functions, equating the two functions, would yield the input value that gives the same output.