a Find the intercepts and plot them on the coordinate plane to draw the line.
B
b In order to find the number of long-sleeved shirts, start with substituting the number of short-sleeved shirts into the equation.
A
aGraph:
Interpretation of the intercepts: See solution.
B
b 15 long-sleeved shirts
Practice makes perfect
a The given equation represents the total cost, where x is the number of short-sleeved shirts and y the number of long-sleeved shirts.
10x+12y=300
In order to graph the equation, we will first determine the intercepts. Let's start with the x-intercept. To find it, we will substitute 0 for y and solve the equation for x.
The y-intercept is at the point (0,25). Finally, we will plot the intercepts and connect them to graph the equation. Notice that the number of the shirts cannot be negative, and thus our graph will be restricted to the first quadrant.
The x-intercept shows that we can order 30 short-sleeved shirts when we do not order any long-sleeved shirts. Similarly, the y-intercept shows that we can order 25 long-sleeved shirts when we do not order any short-sleeved shirts.
b In order to find how many long-sleeved shirts we can order when 12 short-sleeved shirts are ordered, we will substitute 12 for x into the equation. Then, we will solve it for y.
