A number is decreased by seven. Then, the new number is multiplied by 3 to get an answer of -9. What is the original number?
1 answer:
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Answer:
23.05 x 10.85
Step-by-step explanation:
Area of Rectangular Fence = L * W = 250
L * W = 250
W = ................................... (i)
Perimeter = 2L + 2W
Three sides cost 4 dollars per foot = 4(2L) + 4W
(The two lengths must be constructed with the 4 dollars materials)
Fourth side costs 13 dollars per foot = 13W
Cost = 4(2L) + 4W + 13W
C = 8L + 17W ...................................... (ii)
Substitute (i) into (ii)
C = 8L + 17 ()
C = 8L +
Plotting this equation with L on the x-axis and cost on the y-axis
minimum cost will be when L ≈ 23.05 ft
W = ≈ 10.85 ft
minimum cost = 8(23.05) +
minimum cost = 184.4 + 184.382
minimum cost ≈ 368.78 dollars