document.write( "Question 1102648: How much 78 octane gas and 91 octane gas should be blended to make 13 gallons of 87 octane gas? \n" ); document.write( "

Algebra.Com's Answer #717353 by josgarithmetic(39620) $\"\"$ $\"About$

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x, gallons of 78% octane fuel
\n" ); document.write( "13-x, gallons of 91% octane\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"78x%2B91%2813-x%29=87%2A13\"$
\n" ); document.write( "-
\n" ); document.write( " $\"78x%2B91%2A13-91x=87%2A13\"$
\n" ); document.write( " $\"-91x%2B78x=87%2A13-91%2A13\"$
\n" ); document.write( " $\"multiply_by_negative_1\"$
\n" ); document.write( " $\"91x-78x=91%2A13-87%2A13\"$
\n" ); document.write( " $\"13x=4%2A13\"$
\n" ); document.write( " $\"highlight%28x=4%29\"$ ------------ 4 gallons of 78 octane
\n" ); document.write( " $\"highlight%289%29\"$ ----------------9 gallons of 91 octane \n" ); document.write( "

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