Determine their present ages. The sum of the ages of two friends is 20 years. Four years ago, the product of their ages in years was 48.

Explanation

To solve the problem of determining the present ages of two friends given the conditions, we can follow these steps:

### Step 1: Define the Variables
Let the present age of the first friend be \( x \) years and the present age of the second friend be \( y \) years.

### Step 2: Set Up the Equations
From the problem, we know:
1. The sum of their ages is 20 years:
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