Question 47·Medium·Linear Inequalities in One or Two Variables
A food truck plans to prepare burritos and tacos for lunch.
- Each burrito takes minutes to prepare, and each taco takes minutes.
- The truck has at most minutes of prep time.
- The truck wants to prepare at least total items.
Which ordered pair satisfies both conditions?
For linear-inequality word problems with two variables, translate each condition into an inequality, then test the answer choices by substitution. The correct ordered pair must satisfy every inequality at the same time.
Hints
Turn words into inequalities
Write one inequality for the time limit and another inequality for the minimum total number of items.
Use substitution
For each answer choice, substitute its and values into both inequalities.
Both conditions must be true
Eliminate any option that fails either inequality, even if it satisfies the other one.
Desmos Guide
Enter the inequalities
In Desmos, enter and .
(Optional) Restrict to realistic values
If desired, also enter and since numbers of items can’t be negative.
Check the answer choices as points
Plot each answer choice as a point (for example, type ). The correct choice is the only point that lies in the overlap of the shaded regions.
Step-by-step Explanation
Write the inequalities
Prep-time limit: .
Minimum number of items: .
Test each ordered pair
Check each choice in both inequalities:
- : and (works)
- : (fails)
- : (fails)
- : (fails)
Select the pair that satisfies both
Therefore, the ordered pair that satisfies both conditions is .