Question 756942: the area of a rectangular field is 900 sq.m. if the length be diminished by 6m and breadth be increased by 5m it becomes a square. find the perimeter of the rectangular field
Answer by ptaylor(2198)   (Show Source):
You can put this solution on YOUR website! Area of rectangle (A) equals length(L) times width(W) or A=LW
Let L be the length of rectangle
and Let W be the width
Sooo, A=LW=900 sq m.----------------------eq1
Length diminished by 6m=L-6
Width increased by 5m=W+5
Now we know that the length and width of a square are equal, so:
L-6=W+5---------------------------------eq2
From eq 1, W=900/L; substitute this into eq2
L-6=(900/L)+5 multiply each term by L
L^2-6L=900+5L put the quadratic in standard form
L^2-11L-900=0 and this can be factored
(L+25)(L-36)=0
L=-25m-----------------------------no good lengths are positive
L=36m----Length of rectangle
Substitute into eq1, we get W=25m---Width of rectangle
Perimeter would be 2*36+2*25=122m
CK
36-6=30
25+5=30
36*25=900
Hope this helps---ptaylor
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