the width of a rectangle is 9 inches less than its length and the area is 36 square inches. what are the length and width of the rectangle

Respuesta :

Answer:

12  and 3

Step-by-step explanation:

Let  x= length

If you draw a rectangle.  two sides would be the length x.  The other two sides would be (x-9).

(length)(width) = Area

(x)(x-9) = 36

x^2 - 9x = 36 Substitute in x and x-9 for the length and width

x^2 - 9x - 36 =0  Subtract 36 from both sides

(x-12)(x+3) = 0   We are looking for 2 number that add to -9 and mult. to -36

x-12=0 and x+3=0  Set both factors to 0 and solve

x = 12 and x =-3.  It does not make sense that a length could be -3 so we reject that answer.  If the length is 12, then the width is 3