Respuesta :
Given the area, the equation that Noor should use to determine the width of pen is x² + 3x = 70.
The length and width of the rectangular pen are 10m and 7m respectively.
What is the width of the rectangular pen?
The area of a rectangle is expressed as;
A = l × w
Where l is length and w is width.
Given the data in the question;
Let the width of the rectangular pen be 'x'
- Width = w = x
- Length = l = x + 3
- Area = 70m²
To determine the equation that Noor will use to find the width of the pen, plug the values into the equation above.
A = l × w
70 = (x+3) × x
70 = x² + 3x
x² + 3x = 70
We can go further and solve for the width of the pen.
x² + 3x = 70
x² + 3x - 70 = 0
Factor sing AC method; find two integer whose addition gives 3 and multiplication gives -70.
-7 and 10
(x-7) (x+10) = 0
x - 7 = 0, x + 10 = 0
x = 7, x = -10
But the dimension of the width can not be negative.
Hence
x = 7
Width = x = 7m
Length x + 3 = 7 + 3 = 10m
Given the area, the equation that Noor should use to determine the width of pen is x² + 3x = 70.
The length and width of the rectangular pen are 10m and 7m respectively.
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