Q:

Ezra works two summer jobs to save for a laptop that costs at least $1100. He charges $15/hr to mow lawns and $10/hr to walk dogs. Recall the inequality that represents this situation: 15x + 10y ≥ 1100Explain how to graph the solution set.

Accepted Solution

A:
The first step is to ignore the inequality symbol first and replace it with '=' sign. Then, find the x- and y-intercepts.

15x + 10y = 1,100
x-intercept:
15x + 0 = 1,100
x = 1,100/15 = 73.33
y-intercept:
0 + 10y = 1,100
y = 1,100/10 = 110

Now, plot points (73.33,0) and (0,110). Since the equality symbol is ≥, which has an equal sign to it, connect the points using a solid line. 

Next, let's find a point on the graph. Suppose it is the origin at (0,0). Use this points to the equation.
15x + 10y ≥ 1,100
15(0) + 10(0) ? 1,100
0 ? 1,100
0 < 1,100
It makes the symbol ≥ false. Therefore, it means that the other region bounded by the line is the solution. So, you shade this area. The final graph is shown in the picture attached.