9514 1404 393
Answer:
a) w(4w-15)
b) w²
c) w(4w -15) = w²
d) w = 5
e) 5 by 5
Step-by-step explanation:
a) If w is the width, and the length is 15 less than 4 times the width, then the length is 4w-15. The area is the product of length and width.
A = w(4w -15)
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b) If w is the side length, the area of the square is (also) the product of length and width:
A = w²
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c) Equating the expressions for area, we have ...
w(4w -15) = w²
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d) we can subtract the right side to get ...
4w² -15w -w² = 0
3w(w -5) = 0
This has solutions w=0 and w=5. Only the positive solution is sensible in this problem.
The side length of the square is 5 units.
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e) The rectangle is 5 units wide, and 4(5)-15 = 5 units long.
The rectangle and square have the same width and the same area, so the rectangle must be a square.
