Answer:
x² + 12
48m²
Step-by-step explanation:
Find the diagram attached.
The room can be segregated into two rectangles
The area of the room = Area of bottom rectangle + area of the top rectangle
Area of the bottom rectangle = x * (x-3) = x² - 3x
Area of the top rectangle = 3* (4+x) = 12 + 3x
The area of the room = x² - 3x + 12 + 3x
Area of the room = x² + 12
Hence the algebraic expression that the architect can use to find the area of the room is x² + 12
Given x = 6m
The area of the room = x² + 12
The area of the room = 6² + 12
The area of the room = 36 + 12
The area of the room = 48m²