document.write( "Question 221397: Joseph mixes a certain amount of 10% isopropyl mixture with 60 gallons of a 20% isopropyl solution, and the resulting mixture is 16% isopropyl. How much of the 10% isopropyl did he add? To earn credit, you MUST construct an algebraic equation with a variable and solve using algebra steps. \n" ); document.write( "

Algebra.Com's Answer #166065 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"x\"$ = gallons of 10% mixture to be added
\n" ); document.write( "given:
\n" ); document.write( "Iso in 20% mix = $\".2%2A60+=+12\"$
\n" ); document.write( "Iso in 10% mix = $\".1x\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "In words
\n" ); document.write( "(iso in 10% mix)+(iso in 20% mix)/(total gallons of mix) = 16%
\n" ); document.write( " $\"%2812+%2B+.1x%29%2F%2860+%2B+x%29+=+.16\"$
\n" ); document.write( " $\"12+%2B+.1x+=+.16%2A%2860+%2B+x%29\"$
\n" ); document.write( " $\"12+%2B+.1x+=+9.6+%2B+.16x\"$
\n" ); document.write( " $\".06x+=+2.4\"$
\n" ); document.write( " $\"x+=+40\"$
\n" ); document.write( "He must add 40 gallons of the iso mix
\n" ); document.write( "check answer
\n" ); document.write( " $\"%2812+%2B+.1x%29%2F%2860+%2B+x%29+=+.16\"$
\n" ); document.write( " $\"%2812+%2B+.1%2A40%29%2F%2860+%2B+40%29+=+.16\"$
\n" ); document.write( " $\"%2812+%2B+4%29%2F100+=+.16\"$
\n" ); document.write( " $\"16%2F100+=+.16\"$
\n" ); document.write( " $\".16+=+.16\"$
\n" ); document.write( "OK \n" ); document.write( "

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