Solve the following equations :
`15+x=5x+3`

Answer

To solve the equation \( 15 + x = 5x + 3 \), we will follow these steps:

### Step 1: Write down the equation
We start with the equation:
\[ 15 + x = 5x + 3 \]

### Step 2: Move constants to one side
We want to isolate the variable \( x \). To do this, we can subtract \( 3 \) from both sides of the equation:
\[ 15 + x - 3 = 5x + 3 - 3 \]
This simplifies to:
\[ 12 + x = 5x \]

### Step 3: Move the variable terms to one side
Next, we want to get all the \( x \) terms on one side. We can do this by subtracting \( x \) from both sides:
\[ 12 + x - x = 5x - x \]
This simplifies to:
\[ 12 = 4x \]

### Step 4: Solve for \( x \)
Now, we need to isolate \( x \). We can do this by dividing both sides by \( 4 \):
\[ \frac{12}{4} = \frac{4x}{4} \]
This simplifies to:
\[ 3 = x \]

### Step 5: Write the final answer
Thus, the solution to the equation \( 15 + x = 5x + 3 \) is:
\[ x = 3 \]

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