document.write( "Question 495151: Please help me solve this mixture word problem:
\n" ); document.write( "A certain mixture consists of acid and water. If 5 gallons of acid is added to the mixture, it willl produce a mixture that is one-half acid and one-half water. If, on the other hand, 5 gallons of water is added, the resulting mixture is one-third acid. How many gallons of acid does the original mixture contain?
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Algebra.Com's Answer #336049 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
A certain mixture consists of acid and water.
\n" ); document.write( " If 5 gallons of acid is added to the mixture, it will produce a mixture that is one-half acid and one-half water.
\n" ); document.write( " If, on the other hand, 5 gallons of water is added, the resulting mixture is one-third acid.
\n" ); document.write( " How many gallons of acid does the original mixture contain?
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\n" ); document.write( "Let x = the decimal value of of the percent acid in the original mixture
\n" ); document.write( "Let y = the amt (in gallons of the original mixture)
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\n" ); document.write( "write an equation for each statement, based on the amt of acid:
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\n" ); document.write( "\"If 5 gallons of acid is added to the mixture, it will produce a mixture that is one-half acid and one-half water.\"
\n" ); document.write( "xy + 5 = .5(y+5)
\n" ); document.write( "xy + 5 = .5y + 2.5
\n" ); document.write( "xy = .5y + 2.5 - 5
\n" ); document.write( "xy = .5y - 2.5
\n" ); document.write( "x = \"%28%28.5y-2.5%29%29%2Fy\"
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\n" ); document.write( "\"If, on the other hand, 5 gallons of water is added, the resulting mixture is one-third acid.\"
\n" ); document.write( "xy = \"1%2F3\"(y+5)
\n" ); document.write( "3xy = y + 5
\n" ); document.write( "replace x with \"%28%28.5y-2.5%29%29%2Fy\"; find y
\n" ); document.write( "3y(\"%28%28.5y-2.5%29%29%2Fy\") = y + 5
\n" ); document.write( "y cancels (fortunately) so we have
\n" ); document.write( "3(.5y - 2.5) = y + 5
\n" ); document.write( "1.5y - 7.5 = y + 5
\n" ); document.write( "1.5y - y = 5 + 7.5
\n" ); document.write( ".5y = 12.5
\n" ); document.write( "multiply both side by 2
\n" ); document.write( "y = 25 gal is the amt of the original mixture
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\n" ); document.write( "Find x using x = \"%28%28.5y-2.5%29%29%2Fy\"
\n" ); document.write( "x = \"%28%28.5%2825%29-2.5%29%29%2F25\"
\n" ); document.write( "x = \"%28%2812.5-2.5%29%29%2F25\"
\n" ); document.write( "x = \"10%2F25\"
\n" ); document.write( "x = .4, the original mixture was 40% acid
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\n" ); document.write( "See if that checks out in the first statement
\n" ); document.write( "If 5 gallons of acid is added to the mixture, it will produce a mixture that is one-half acid and one-half water.\"
\n" ); document.write( ".4(25) + 5 = .5(25 + 5)
\n" ); document.write( "10 + 5 = .5(30); confirms our solution
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\n" ); document.write( "An interesting problem (Most of them aren't)
\n" ); document.write( "Did all this make sense to you? Make an effort to understand each step, ask me in the comment section, if you have a question. C
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