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.
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'
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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