## Intermediate Algebra (12th Edition)

A line in slope-intercept form has the equation: $y=mx+b$ ($m=slope$, $b=y-intercept$) We put our first equation into slope-intercept form: $x+y\leq 1$ $y\leq -x+1$ Thus we graph a line with $slope=-1$ and $y-intercept=1$. We know that if an inequality has an "equal" sign (e.g. "$\leq$" or "$\geq$"), then a solid line should be graphed. If the inequality does not have an "equal" sign (e.g. "$\lt$" or "$\gt$"), then a dashed line should be graphed. We also know that if an inequality has a "less than" sign (e.g. "$y\lt$..." or "$y\leq$..." or "$x\lt$..." or "$x\leq$..."), then the shading should be below the line (or left for vertical lines). If the inequality has a "greater than" sign (e.g. "$y\gt$..." or "$y\geq$..." or "$x\gt$..." or "$x\geq$..."), then the shading should be above the line (or right for vertical lines). In our case, we must graph a solid line and shade below. Next, we look at our second equation: $x\geq 1$ This has the form of a vertical line ($x=constant$) going through $x=1$. We see from the inequality that we must graph a solid line and shade right. See the resulting graph. The dark region is the area where both inequalities overlap (e.g. the solution region). 