document.write( "Question 185924: the fuel efficiency of an average car is given by y= -0.0177x*2 + 1.48x + 3.39 where x is the speed im miles per hour and y is the fuel economy in miles per gallon.
\n" ); document.write( "1. find the speed at which an average car will get 20 mi/gal
\n" ); document.write( "2. what speed yields the best fuel economy?
\n" ); document.write( "3. determine the range of speeds that yield 32 mi/gal or better\r
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\n" ); document.write( "\n" ); document.write( "please answer
\n" ); document.write( "tHaNk yOU \n" ); document.write( "
Algebra.Com's Answer #139415 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
the fuel efficiency of an average car is given by y= -0.0177x*2 + 1.48x + 3.39 where x is the speed im miles per hour and y is the fuel economy in miles per gallon.
\n" ); document.write( "1. find the speed at which an average car will get 20 mi/gal
\n" ); document.write( "solve -0.0177x*2 + 1.48x + 3.39 = 20
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\n" ); document.write( "If that equation is really a quadratic there are two solutions:
\n" ); document.write( "x = 70.26 mph and x = 13.36 mph
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\n" ); document.write( "2. what speed yields the best fuel economy?
\n" ); document.write( "x = -b/2a = -1.48/(2*-0.0177) = 41.81 mph
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\n" ); document.write( "\n" ); document.write( "3. determine the range of speeds that yield 32 mi/gal or better
\n" ); document.write( "33.34 <= x <= 53.28
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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