Using a system of equations, it is found that David is 12 years old.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
The variables are given as follows:
- Variable z: Rebecca's age.
David is three times younger than the dad and twice as old as Rebecca, then:
Rebecca is 30 years younger than the dad, hence:
z = y - 30.
Then, since x = 2z and z = y - 30 and y = 3x, we solve for x to find David's age.
x = 2(y - 30)
x = 2(3x - 30)
x = 6x - 60
5x = 60
x = 60/5
x = 12.
David is 12 years old.
More can be learned about a system of equations at brainly.com/question/24342899
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Answer:
31,000 on apex
Step-by-step explanation:
Answer:
x = 12
Step-by-step explanation:
The exterior angles of any polygon always add up to 360, so:

Rachel could get 8 ounce of cheese
Step-by-step explanation:
Step 1:
Let Rachel will pay $0.36 per ounce for cheese.
In option A, for 8 oz of cheese, it is $ 2.88.
Step 2:
Here, for 8 oz of cheese
2.88/8 = 0.36 .