Question 920183
The perimeter formula for a rectangle is 


P = 2*(L+W) 


where L is the length and W is the width.



Since "The length of a rectangle is 15cm longer than two times its width" and "the perimeter of the rectangle is 252m", we know 


W = x
L = 2x+15
P = 252


where x is some unknown number for now. Plug those values into P = 2*(L+W) and solve for x.



P = 2*(L+W)


252 = 2*(2x+15+x)


252 = 2*(3x+15)


252 = 6x+30


252-30 = 6x+30-30


222 = 6x


6x = 222


x = 222/6


x = 37


Now that we know x = 37, we can use this to find L and W. Recall that above we made


W = x
L = 2x+15


Since W = x and x = 37, we know W = 37. 


Use this x value to find L


L = 2x+15


L = 2(37)+15


L = 74+15


L = 89


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Final Answer:


So the length is 89 and the width is 37.



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Thanks,


Jim