document.write( "Question 481250: Hi thank you for your time! Here is the problem I am working on. WIll you show me how you come up with your solutions? Thank you again so much for your time!\r
\n" ); document.write( "\n" ); document.write( "The world consumption of oil in millions of barrels per day is given by
\n" ); document.write( "f(x)=-0.1x^2 + 2x + 58, where x is the number of years since 1985 (x=0 for 1985)\r
\n" ); document.write( "\n" ); document.write( "a. According to this equation, what was the oil consumption in 1990?
\n" ); document.write( "b. Using this equation, the maximum oil consumption will occur in what year?
\n" ); document.write( "c. What is the maximum oil consumption?
\n" ); document.write( "d. Does this equation realistically describe oil in 2030? why or why not?
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Algebra.Com's Answer #329534 by nerdybill(7384)\"\" \"About 
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f(x)=-0.1x^2 + 2x + 58, where x is the number of years since 1985 (x=0 for 1985)
\n" ); document.write( "a. According to this equation, what was the oil consumption in 1990?
\n" ); document.write( "1990 - 1985 = 5
\n" ); document.write( "set x = 5 and solve f(5)
\n" ); document.write( "f(x)=-0.1x^2 + 2x + 58
\n" ); document.write( "f(5)=-0.1(5)^2 + 2(5) + 58
\n" ); document.write( "f(5)=-0.1(25) + 10 + 58
\n" ); document.write( "f(5)= 65.5 million barrels
\n" ); document.write( ".
\n" ); document.write( "b. Using this equation, the maximum oil consumption will occur in what year?
\n" ); document.write( "It would be the vertex.
\n" ); document.write( "x = -b/(2a)
\n" ); document.write( "x = -2/(2(-0.1))
\n" ); document.write( "x = -2/(-0.2)
\n" ); document.write( "x = 10
\n" ); document.write( "year:
\n" ); document.write( "1985 + 10 = 1995
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\n" ); document.write( "c. What is the maximum oil consumption?
\n" ); document.write( "set x = 10 solve for f(x)
\n" ); document.write( "f(x)=-0.1x^2 + 2x + 58
\n" ); document.write( "f(5)=-0.1(10)^2 + 2(10) + 58
\n" ); document.write( "f(5)=-0.1(100) + 20 + 58
\n" ); document.write( "f(5)= 68 million barrels
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\n" ); document.write( "d. Does this equation realistically describe oil in 2030? why or why not?
\n" ); document.write( "2030-1985 = 45
\n" ); document.write( "set x = 45 solve for f(x)
\n" ); document.write( "f(x)=-0.1x^2 + 2x + 58
\n" ); document.write( "f(5)=-0.1(45)^2 + 2(45) + 58
\n" ); document.write( "f(5)=-0.1(2025) + 90 + 58
\n" ); document.write( "f(5)=-54.5 million barrels
\n" ); document.write( "answer: NO, because the result is negative
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