If we sum both equations, we have the next result:
[tex]0\text{ = 0}[/tex]Since we have this, we can say that the system has infinite solutions. We sum both equations, and we finally get that 0 = 0. In this case, the system has infinite solutions.
All these solutions are expressed by (solving for y):
[tex]y=\text{ 1 + 5x}[/tex]For example, for a value of x = 1, y is a function of x; then, y = 1 + 5 = 6, or (1, 6), and so on.
For the next system of equations:
[tex]\begin{gathered} x\text{ + 2y = 13} \\ -x\text{ + 2y = 7} \end{gathered}[/tex]Adding both equations, we finally have:
[tex]4y\text{ = 20}\Rightarrow\text{ y = 5}[/tex]Then, solving for x, we have (using the first equation):
[tex]x\text{ + 2(5) = 13 }\Rightarrow x\text{ = 13 - 10 }\Rightarrow x\text{ = 3}[/tex]Then, this last system has a unique solution, which is (3, 5) or x = 3 and y = 5.