Write the equation x = 7 in two variables. 

If an equation is written in the form $ax+by+c=0$, it is said to be a linear equation in two variables, where $a,b, and c$ are real integers and the coefficients of $x and y$, i.e. a and b are not equal to zero.
It is given that the equation is x=7.
$x=7$can be written as;
$1·x+0.y=7$
Here, the coefficient of x is 1 and that of y is 0 .
Thus, the equation x=7 can be written in two variables as $1·x+0.y=7$