Which of the following are a pair of linear equations in two variables?
12x + 4y + 3 = 0; 4x + 4y + 4 = 0
Equations which are linear with same two variables are called pair of linear equation in two variables.
12x + 4y + 3 = 0 and 4x + 4y + 4 = 0 are linear equations in same two variables.