# Linear Equation with Two Variables and Its Graph

Equation of the form ax+by=c, where x,y are variables and a,b,c are numbers, is called linear; numbers a adn b are called coefficients near variables, number c is called free member.

Graph of any linear equation ax+by=c, where at least one coeffcient doesn't equal zero, is line; if a=0, then line is parallel to the x-axis, if b=0, then it is parallel to th y-axis (see figure to the right).

Example. Draw graph of the equation 2x-3y=-6.

Graph of this equation is line. To draw line it is sufficiently to know two its points.

If x=0 then 2*0-3y=-6 or y=2. Thus, first point is (0;2).

If y=0 then 2x-3*0=-6 or x=-3. Thus, second point is (-3;0).

Drawing line through these two points, will give graph of the given equation.