Answer:
Length = 15
Width = 6
Area = 90
Step-by-step explanation:
Area of the rectangle = [tex] {x}^{2} + 3x - 6x - 18[/tex]
Lets factorise the polynomial
[tex] = > x(x + 3) - 6(x + 3)[/tex]
[tex] = > (x + 3)(x - 6)[/tex]
We know that Area = Length × Width
Let the length be (x + 3) & width be (x - 6)
Its given in the question that x = 12. So putting the value of x gives ,
Length = [tex]x + 3 = 12 + 3 = 15[/tex]
Width = [tex]x - 6 = 12 - 6 = 6[/tex]
Area = Length × Width = 15 × 6 = 90