Solving linear equations
The solution of linear equations with one variable is any number $x$ that satisfies the equation.
Given is a linear equation$x-8=8$
Use appropriate value$x=16$
If you use 16 for $x$ , the equation is true.
Computationally one can solve a linear equation with an equivalent transformation.
The solution of linear equations with two variables is every value pair $x|y$ that satisfies the equation.
Given is a linear equation with two variables$x+y=6$
Use appropriate valuese. g. $x=4$ and $y=2$
If one uses for $x$ 4 and $y$ 2, the equation is satisfied. The value pair $4|2$ is a solution.
But: There are endless possibilities for $x$ and $y$.
Computationally one can solve two linear equations with two variables with one system of linear equations.