Answer:
Explanation:
You want a system of equations that represents the relations between Sally's age and Jerry's age.
First step
The first step in dealing with a word problem is to engage your brain. There can be a tendency to start by saying "I can't do this!", which will turn off your brain and guarantee that you will have trouble. If you realize the words have their usual English meaning, then understanding what they are saying is not so hard.
Second step
Once you have read the question and identified what it is asking for (equations for ages), then you can figure out what to do. Usually, you will want to assign tokens (variables) for the things that are being asked for (ages).
It is often convenient to choose variables that remind you what they stand for. Here, it is convenient to use S for Sally's age, and J for Jerry's age. Your answer to the question will be equations that relate S and J.
Third step
Now you can get into the details of the relationships that are being described.
A sum is the addition of two or more items. Here the items are (Sally's age) and (twice Jerry's age). Twice means "two times," so "twice Jerry's age" will be represented by 2×J, or simply 2J. That sum is ...
S + 2J . . . . . . "sum of Sally's age plus twice Jerry's age"
The problem tells us this is 48, so the first equation is ...
S + 2J = 48
The wording of the second sentence tells you how to write the second equation:
Sally's age minus Jerry's age is 3
S - J = 3
Summary
The system of equations you're looking for is ...
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Additional comment
In general, if you want to obtain a solution, you will need as many equations as there are variables. Here, the problem statement gives two relations in two sentences. Those relations give two equations in the two variables. This is the "system of equations" that is being asked for.