Sign In
Let x represent the number of hours that Louie works as a busboy and y represent the number of hours he works as a clerk. Begin by writing a system of inequalities that represents the situation.
Let x represent the number of hours that Louie works as a busboy and y represent the number of hours he works as a clerk.
| Job | Pay |
|---|---|
| Busboy | $6.50 |
| Clerk | $8.00 |
Knowing that he can work no more than 25, we can say that the sum of the working hours is less than or equal to 25. x+ y ≤ 25 For the inequality that represents the pay, we will make an organized table.
| Verbal Expression | Algebraic Expression |
|---|---|
| Pay after x hours working as a busboy | 6.5 x |
| Pay after y hours working as a clerk | 8 y |
| Total pay must be at least $150. | 6.5 x+ 8 y≥ 150 |
Thus, we have two inequalities to write a system.
| x+y=25 | ||
|---|---|---|
| Operation | x-intercept | y-intercept |
| Substitution | x+ 0=25 | 0+y=25 |
| Calculation | x=25 | y=25 |
| Point | (25,0) | (0,25) |
Now we can plot the intercepts and connect them with a line segment. Notice that number of working hours cannot be negative, so it will be bound by the axes. The boundary line will also be solid because of the non-strict inequality.
Next, we should decide which region we will shade. To do so we will test the point (0,0).
Because the point satisfied the inequality, we will shade the region that contains the point. Let's do it!
The second inequality can be graphed by proceeding in the same way. &Inequality II &&Boundary Line II &6.5x+8y ≥ 150 &&6.5x+8y = 150 Next step is to determine the intercepts.
| 6.5x+8y = 150 | ||
|---|---|---|
| Operation | x-intercept | y-intercept |
| Substitution | 6.5x+8( 0) = 150 | 6.5( 0)+8y = 150 |
| Calculation | x=23.1 | y=18.75 |
| Point | (23.1,0) | (0,18.75) |
Now that we know the intercepts, we should decide which region we will shade as our final step.
x= 0, y= 0
Zero Property of Multiplication
The point did not satisfy the inequality, so we will shade the region that does not contain the point.
The overlapping section is the section that represents the possible combinations.