document.write( "Question 878342: If three straight lines x+2y-1=0 >>> x-y+2=0 >>> ax-y+3=o meet at one point then a= \n" ); document.write( "

Algebra.Com's Answer #529870 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
Find where the first two lines meet.
\n" ); document.write( "Subtract the first equation from the second.
\n" ); document.write( " $\"x-y%2B2-x-2y%2B1=0\"$
\n" ); document.write( " $\"-3y%2B3=0\"$
\n" ); document.write( " $\"-3y=-3\"$
\n" ); document.write( " $\"y=1\"$
\n" ); document.write( "Then,
\n" ); document.write( " $\"x-y%2B2=0\"$
\n" ); document.write( " $\"x-1%2B2=0\"$
\n" ); document.write( " $\"x%2B1=0\"$
\n" ); document.write( " $\"x=-1\"$
\n" ); document.write( "The first two lines meet at (-1,1).
\n" ); document.write( "Now solve for $\"a\"$ .
\n" ); document.write( " $\"a%28-1%29-1%2B3=0\"$
\n" ); document.write( " $\"-a%2B2=0\"$
\n" ); document.write( " $\"-a=-2\"$
\n" ); document.write( " $\"highlight%28a=2%29\"$
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( "

\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );