document.write( "Question 254848: If 3x + y = a and 4x – y = b, then determine the value of y in terms of a and b. \n" ); document.write( "

Algebra.Com's Answer #187148 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"3x+%2B+y+=+a\"$
\n" ); document.write( " $\"4x-y+=+b\"$
\n" ); document.write( "Solve for x in eq. 1 and substitute into eq. 2,
\n" ); document.write( " $\"3x+%2B+y+=+a\"$
\n" ); document.write( " $\"3x++=+a-y\"$
\n" ); document.write( " $\"x=%281%2F3%29%28a-y%29\"$
\n" ); document.write( " $\"4x=%284%2F3%29%28a-y%29\"$
\n" ); document.write( "Now substitute,
\n" ); document.write( " $\"4x-y+=+b\"$
\n" ); document.write( " $\"%284%2F3%29%28a-y%29-y+=+b\"$
\n" ); document.write( " $\"4%28a-y%29-3y+=+3b\"$
\n" ); document.write( " $\"4a-4y-3y=3b\"$
\n" ); document.write( " $\"-7y=3b-4a\"$
\n" ); document.write( " $\"y=%281%2F7%29%284a-3b%29\"$ \n" ); document.write( "

\n" );