Using a system of equations, it is found that Peter had $48 at first.
<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.
In this problem, the variables are:
- Variable x: Peter's money.
- Variable y: Henry's money.
The ratio of peters money to henrys money is 4 : 3, hence:

After Peter spent $12, they had the same amount, hence:
y = x - 12.
Then, replacing in the ratio:


4(x - 12) = 3x
x = 48.
More can be learned about a system of equations at brainly.com/question/24342899
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