Answer:
• (4x-1)(3x+6)
,
• 12x²+21x-6
Step-by-step explanation:
From the diagram
Width of the rectangular room = 3x+6
Length of the rectangular room = 4x-1
Area of a rectangle = Lenght x Width
So, an expression that represents the area of the rectangular room is:
![A=\mleft(4x-1\mright)(3x+6)](https://img.qammunity.org/2023/formulas/mathematics/college/3p7c14qdinhjtungmj3egssdyf6yf7bzbx.png)
To rewrite the expression as a polynomial in standard form, we expand:
![\begin{gathered} A=4x(3x+6)-1(3x+6) \\ =12x^2+24x-3x-6 \\ =12x^2+21x-6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/c664ajcgxpxr3am2p1ie02tpt2jjvx00ed.png)
The polynomial in standard form is: 12x²+21x-6