Define a consistent and independent system of equations. How many solutions does it have?

A system of equations with the same number of unknowns where its equations are consistent with each other and independent is called a consistent and independent system. This type of system has exactly one unique solution.

Answer: consistent and independent

An ordered pair of numbers that is a solution to both equations in a system is called a solution to a system of equations.

Answer: solution

The graph shows that the two lines intersect at the point $(2, 1)$.

Answer: $\boxed{(2, 1)}$

If the lines in a system of equations coincide, they are the same line, meaning every point on the line is a solution. Therefore, the system has infinitely many solutions and is said to be consistent and dependent.

Answer: infinitely many, consistent and dependent