In this formula ` I_n =[a+ (n-1) d] ,` make 'n' as the subject

Answer

To make 'n' the subject of the formula \( I_n = a + (n - 1) d \), we will follow these steps:

### Step 1: Start with the original formula
The original formula is:
\[ I_n = a + (n - 1) d \]

### Step 2: Isolate the term containing 'n'
To isolate the term containing 'n', subtract 'a' from both sides:
\[ I_n - a = (n - 1) d \]

### Step 3: Divide both sides by 'd'
Next, divide both sides by 'd' to isolate \( n - 1 \):
\[ \frac{I_n - a}{d} = n - 1 \]

### Step 4: Solve for 'n'
Now, add 1 to both sides to solve for 'n':
\[ n = \frac{I_n - a}{d} + 1 \]

### Final Result
Thus, the formula for 'n' in terms of \( I_n \), \( a \), and \( d \) is:
\[ n = \frac{I_n - a}{d} + 1 \]

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