The area of rectangle is 110 sq m .If each of its sides is decreased by 4 cm .Then the area 42 sq cm.What is the width of the rectangle?
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Hlw mate!!!
the area of a rectangle is defined as the length times the width. So, let
l: length of rectangle
w: width of rectangle
So, we know that lw=300 (area of rectangle is 300 square meters. I am leaving off the units. In the end, our length and width will both be in meters since meters times meters is square meters.)
Also, we know that
l=2w+1 (the length is one more than twice the width). Substituting this value in for l yields
(2w+1)w=300 which is the same as
2w2+w-300=0 (Distributing and miving everything to one side, since this is a quadratic equation)
Using the quadratic formula gives you w=12 and w=-25/2. Since a width can't be negative, it must be that w=12. Substituting this value into our equation for length gives us
l=2(12)+1=25. Thus length is 25 meters and width is 12 meters. But is this right? need to check!
Does 25*12=300? Yes it does!
Hope it helpful
the area of a rectangle is defined as the length times the width. So, let
l: length of rectangle
w: width of rectangle
So, we know that lw=300 (area of rectangle is 300 square meters. I am leaving off the units. In the end, our length and width will both be in meters since meters times meters is square meters.)
Also, we know that
l=2w+1 (the length is one more than twice the width). Substituting this value in for l yields
(2w+1)w=300 which is the same as
2w2+w-300=0 (Distributing and miving everything to one side, since this is a quadratic equation)
Using the quadratic formula gives you w=12 and w=-25/2. Since a width can't be negative, it must be that w=12. Substituting this value into our equation for length gives us
l=2(12)+1=25. Thus length is 25 meters and width is 12 meters. But is this right? need to check!
Does 25*12=300? Yes it does!
Hope it helpful
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