document.write( "Question 1005253: There are 2 vats of milk, one containing 25% protein and the other 40% protein. These two are to be mixed in order to get 12 liters of a 35% protein content milk. How many liters of each must be used? \n" ); document.write( "

Algebra.Com's Answer #621644 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = liters of 25% protein needed
\n" ); document.write( "Let $\"+b+\"$ = liters of 40% protein needed
\n" ); document.write( "----------------------------------
\n" ); document.write( "(1) $\"+a+%2B+b+=+12+\"$
\n" ); document.write( "(2) $\"+%28+.25a+%2B+.4b+%29+%2F+12+=+.35+\"$
\n" ); document.write( "--------------------------
\n" ); document.write( "(2) $\"+.25a+%2B+.4b+=+.35%2A12+\"$
\n" ); document.write( "(2) $\"+.25a+%2B+.4b+=+4.2+\"$
\n" ); document.write( "(2) $\"+25a+%2B+40b+=+420+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "Multiply both sides of (1) by $\"+25+\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+25a+%2B+40b+=+420+\"$
\n" ); document.write( "(1) $\"+-25a+-+25b+=+-300+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( " $\"+15b+=+120+\"$
\n" ); document.write( " $\"+b+=+8+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+a+%2B+b+=+12+\"$
\n" ); document.write( "(1) $\"+a+=+4+\"$
\n" ); document.write( "---------------
\n" ); document.write( "4 liters of 25% protein are needed
\n" ); document.write( "8 liters of 40% protein are needed
\n" ); document.write( "-----------------------------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+%28+.25a+%2B+.4b+%29+%2F+12+=+.35+\"$
\n" ); document.write( "(2) $\"+%28+.25%2A4+%2B+.4%2A8+%29+%2F+12+=+.35+\"$
\n" ); document.write( "You can finish \n" ); document.write( "

\n" );