## Algebra: A Combined Approach (4th Edition)

$x+y=1$ Substituting $x=0$, $(0)+y=1$ $y=1$ Hence, (0,1) is a point on the graph. $x+y=1$ Substituting $x=1$, $(1)+y=1$ $y=0$ Hence, (1,0) is a point on the graph.
To graph this equation, we find two ordered pair solutions of $x+y=1$. To do this, we choose a value for one variable, x or y, and solve for the other variable. For example, if we let x=0 then $x+y=1$ becomes $x+y=1$ $(0)+y=1$ $y=1$ Since $y=1$ when $x=0$, the ordered pair (0, 1) is a solution of $x+y=1$ Next, we let x=1 $x+y=1$ $(1)+y=1$ $y=0$ The ordered pair (1, 0) is a second solution. The two solutions found so far allow us to draw the straight line that is the graph of all solutions of $x+y=1$