document.write( "Question 178565: what quantity x of an 80% solution must be added to a 15% solution to produce 600mL of a 40% solution \n" ); document.write( "

Algebra.Com's Answer #133522 by Mathtut(3670) $\"\"$ $\"About$

You can put this solution on YOUR website!
what quantity x of an 80% solution must be added to a 15% solution to produce 600mL of a 40% solution
\n" ); document.write( ":
\n" ); document.write( "let x and y be amounts of 80% and 15% solutions respectively
\n" ); document.write( ":
\n" ); document.write( "x+y=600.....eq 1
\n" ); document.write( ".8x+.15y=.4(600)...eq 2
\n" ); document.write( ":
\n" ); document.write( "rewrite eq 1 to x=600-y and place that value into eq 2
\n" ); document.write( ":
\n" ); document.write( ".8(600-y)+.15y=.4(600)
\n" ); document.write( ":
\n" ); document.write( "480-.8y+.15y=240
\n" ); document.write( ":
\n" ); document.write( "-.65y=-240
\n" ); document.write( ":
\n" ); document.write( " $\"y=369.23\"$ ml of 15% solution
\n" ); document.write( ":
\n" ); document.write( "x=600-y $\"x=600-369.23=highlight%28230.77%29\"$ ml of 80% solution \n" ); document.write( "

\n" );