Ans: \(8x-10\) or \(2(4x-5)\)
The perimeter \( P \) of a rectangle is calculated using the formula:
\[ P = 2(\text{Length} + \text{Width}) \]
Substitute the given expressions for length (\(3x – 12\)) and width (\(x + 7\)):
\[ P = 2((3x – 12) + (x + 7)) \]
Simplify the expression inside the parentheses:
\[ P = 2(4x – 5) \]
Finally, expand to get the simplest form:
\[ P = 8x – 10 \]
