If you are asking for the area of the rectangle...
Let L = Length
Let W = Width
Let A = Area of rectangle
A = LW
A = ( 2x + 3 ) ( 4x - 1 )
A = 8x^2 - 2x + 12x - 3
A = 8x^2 + 10x - 3
If you are asking for the perimeter of the rectangle...
Let L = Length
Let W = Width
Let P = Perimeter of rectangle
P = 2L + 2W
P = 2 ( 2x + 3 ) + 2 ( 4x - 1 )
P = 4x + 6 + 8x - 2
Expanded form -
P = 12x + 4
Factorised form -
P = 4 ( 3x + 1 )
Hope this helps! :)
Have a lovely day! <3