document.write( "Question 769271: how much 20% acid must be mixed with 5% acid to make 30mL of 12% acid? \n" ); document.write( "

Algebra.Com's Answer #468820 by josgarithmetic(39618) $\"\"$ $\"About$

You can put this solution on YOUR website!
ASSIGN VARIABLES TO ALL QUANTITIES
\n" ); document.write( "L, the lower concentration of available material
\n" ); document.write( "H, the higher concentration of available material
\n" ); document.write( "T, the target concentration of resulting mixture
\n" ); document.write( "x, the amount of lower concentrated material to use, unknown
\n" ); document.write( "y, the amount of higher concentrated materaial to use, unknown
\n" ); document.write( "M, amount of the resulting mixture\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "FORM EQUATIONS
\n" ); document.write( " $\"highlight%28%28Lx%2ByH%29%2FM=T%29\"$
\n" ); document.write( " $\"highlight%28x%2By=M%29\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Most of the symbolic solution process:
\n" ); document.write( " $\"%28Lx%2ByH%29%2FM=T\"$
\n" ); document.write( " $\"Lx%2ByH=TM\"$
\n" ); document.write( " $\"Lx%2B%28M-x%29H=TM\"$
\n" ); document.write( " $\"Lx%2BHM-Hx=TM\"$
\n" ); document.write( " $\"%28L-H%29x%2BHM=TM\"$
\n" ); document.write( " $\"%28L-H%29x=TM-HM\"$
\n" ); document.write( " $\"%28L-H%29x=%28T-H%29M\"$
\n" ); document.write( " $\"x=M%28T-H%29%2F%28L-H%29\"$ , and since the two differences here would both be negative,
\n" ); document.write( "we can multiply by (-1)/(-1),
\n" ); document.write( " $\"x=M%28H-T%29%2F%28H-L%29\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Do what you need to find y.
\n" ); document.write( "Substitute given values for finding values of x and y. \n" ); document.write( "

\n" );