Question

Sarah walks into a grocery store with no more than 20 dollars to spend and needs to buy at least 3.5 pounds of flour and at least 2 pounds of sugar. Flour is 2 dollars per pound and sugar is 1.5 dollars per pound. Let x the amount of flour purchased and y be the amount of sugar purchased? Which of the following systems of inequalities represents this situation?

Answer 1

Answer: x ≥ 3.5

y ≥ 2

2x + 1.5y ≤ 20

Step-by-step explanation: To write a system of inequalities, it is important to determine the restrictions. One restriction is that Sarah wants to buy at least 3.5 pounds of flour. "At least" means that 3.5 is the smallest amount she would buy and 3.5 can be included. This is expressed as x ≥ 3.5. She also wants at least 2 pounds of sugar, so similar to the flour, this can be written as y ≥ 2. Finally, the cost can be expressed as 2x + 1.5y. This is a restriction because Sarah can spend up to $20, so 2x + 1.5y is less than or equal to $20, or 2x + 1.5y ≤ 20.

Answer 2

x ≥ 3.5

y ≥ 2

2x + 1.5y ≤ 20

Explanation:

Given :

Total Amount to spend ≤ $20

Let:

Amount of flour purchased = x

Amount of sugar purchased = y

Cost :

Flour = $2 per pound

Sugar = $1.5 per pound

Pounds of :

flour to be purchased ≥ 3.5

Sugar to be purchased ≥ 2

Hence, the system of inequalities :

x ≥ 3.5

y ≥ 2

Total Cost of x + total cost of y must be less than or equal to total amount

2x + 1.5y ≤ 20