document.write( "Question 14427: The total cost of 8 gallons of regular unleaded gasoline and 12 gallons of premium unleaded is $27.84. premium unleaded gasoline costs $0.17 more per gallon than regular unleaded. Find the price per gallon for each grade of gasoline. Please show how to set this equation up and answer it. \n" ); document.write( "

Algebra.Com's Answer #7223 by LilSkittleMd(119) $\"\"$ $\"About$

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Let r=regular, p=premium
\n" ); document.write( "First set up the two equations
\n" ); document.write( "8r+12p=27.84
\n" ); document.write( "p=r+0.17
\n" ); document.write( "Substitute for p
\n" ); document.write( "8r+12(r+0.17)=27.84
\n" ); document.write( "Distribute
\n" ); document.write( "8r+12r+2.04=27.84
\n" ); document.write( "Combine like terms
\n" ); document.write( "20r+2.04=27.84
\n" ); document.write( "Subtract 2.04 from both sides of the equation
\n" ); document.write( "20r=25.80
\n" ); document.write( "Divide both sides of the equation by 20
\n" ); document.write( "r=1.29
\n" ); document.write( "Now plug in the value for r into one of the original equations
\n" ); document.write( "p=1.29+0.17
\n" ); document.write( "p=1.46
\n" ); document.write( "One gallon of regular unleaded gasoline is $1.29
\n" ); document.write( "One gallon of premium unleaded gasoline is $1.46 \n" ); document.write( "

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