A field with an area of 1800m² has the shape of a rectangle, whose length is 5m greater than its width. find the dimensions of this field. you probably have a mistake in the highlighted field(s).

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L=W+5

A=LW, and using L from above this becomes:

A=(W+5)W

A=W^2+5W and we are told A=1800 so:

W^2+5W=1800

W^2+5W-1800=0  factor

W^2+45W-40W-1800=0

W(W+45)-40(W+45)=0

(W-40)(W+45)=0  Since length cannot have a negative value in this problem (because it would have no meaning)

W=40m, and we were told L=W+5, L=45m

The dimensions of the rectangle field, whose length is 5m greater than its width and area 1800 m² is 45×40 meters.  

What is the area of a rectangle?

Area of a rectangle is the product of the length of the rectangle and the width of the rectangle. It can be given as,

[tex]A=a\times b[/tex]

Here, (a)is the length of the rectangle and (b) is the width of the rectangle

Suppose the dimension of the field is x×y, where x is the length and y is the width of the field.

As, the area of the field is 1800 m². Therefore,

[tex]xy=1800\\x=\dfrac{1800}{y}[/tex]        ....1

The length of this field  is 5 m greater than its width. Therefore,

[tex]x=y+5[/tex]

Put the value of x from the equation 1 in the above expression as,

[tex]\dfrac{1800}{y}=y+5\\y^2+5y-1800=0\\y^2+45y-40y-1800=0\\y(y+45)-40(y+45)=0\\(y+45)(y-40)=0[/tex]

By equation the values, we get the width -45 and 40. As the width can not be negative. Thus, the width of the field is 40 m.

Put this value in equation one as,

[tex]x=40+5\\x=45[/tex]

Hence, the dimensions of the rectangle field, whose length is 5m greater than its width and area 1800 m² is 45×40 meters.  

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