TSI A2 Mathematics Practice Test

In chart graphing, relationships between x and y are described by equations that can tie both variables together. The formula does not have to isolate one variable; x and y can both appear in the expression. For example, a circle is given by x^2 + y^2 = 25, which involves both x and y and describes all points that satisfy the relationship. Even lines can be written implicitly with both variables, showing the same idea.

Therefore, it’s true that the formula involving x and y does not have to have only one variable; both can be part of the relation. This is why the statement is correct. The method can use algebraic formulas, and it isn’t restricted to only x or only y.