document.write( "Question 550950: Jackie mixes some 35% acid solution with some 70% acid solution to make 100mL of a 42% acid solution. How much of the 35% acid solution did she use? \n" ); document.write( "
Algebra.Com's Answer #359268 by Maths68(1474)\"\" \"About 
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Solution A
\n" ); document.write( "Amount = x ml
\n" ); document.write( "Concentration =35% =0.35\r
\n" ); document.write( "\n" ); document.write( "Solution B
\n" ); document.write( "Amount = 100-x ml
\n" ); document.write( "Concentration =70% = 0.7\r
\n" ); document.write( "\n" ); document.write( "Resultant Solution
\n" ); document.write( "Amount =100ml
\n" ); document.write( "Concentration =42%=0.42\r
\n" ); document.write( "\n" ); document.write( "[Amount Solution A * Concentration A] + [Amount Solution B * Concentration of B] = Amount of Resultant * Concentration of resultant
\n" ); document.write( "(x)(0.35)+(0.7)(100-x)=100*.42
\n" ); document.write( "0.35x+70-0.7x=42
\n" ); document.write( "0.35x-0.7x=42-70
\n" ); document.write( "-0.35x=-28
\n" ); document.write( "-0.35x/-0.35=-28/-0.35
\n" ); document.write( "x=80\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Jackie used 80ml of 35% acid solution and 20ml of 70% acid solution to make 100ml of a 42% acid solution.
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