A linear equation is a equation which can be written in the form , ax+b=0 , x is a variable.
Also, a linear equation can also be written in two variables as of form, ax+by=0 here, x,y are variables.
The system of linear equation is when there are two or more than two linear equations are involved like,
So, we have two linear equation in two variables x and y.
Also, the linear equation has variables with the max power of variables as 1 then its a linear equation.
So, a system of linear equation with one or two variable can be written as two or more than two linear equations together.