document.write( "Question 322079: Find an equation of the line containing the point (1,-2) and parallel to the line 9x-3y=5. Show work and explain each step. Please help!!!!!!!Don't not understand...Thanks \n" ); document.write( "

Algebra.Com's Answer #230555 by Jk22(389) $\"\"$ $\"About$

You can put this solution on YOUR website!
A line is given by : set of (x,y)=OP+a*(dx,dy)\r
\n" ); document.write( "\n" ); document.write( "OP is a point of the line, (dx,dy) is the vector giving the direction of the line.\r
\n" ); document.write( "\n" ); document.write( "we need 2 points of the line : e.g. OP=(0,-5/3) and OP1=(1,4/3)\r
\n" ); document.write( "\n" ); document.write( "hence : (dx,dy)=(1,3)\r
\n" ); document.write( "\n" ); document.write( "---------------------\r
\n" ); document.write( "\n" ); document.write( "For the seeked line we put OP2=(1,-2) and the same vector of direction, to be parallel : \r
\n" ); document.write( "\n" ); document.write( "line 2 is the set of :(x2,y2)=(1,-2)+a(1,3)\r
\n" ); document.write( "\n" ); document.write( "x2=1+a
\n" ); document.write( "y2=-2+3a\r
\n" ); document.write( "\n" ); document.write( "eliminate a : 3x2-y2=5\r
\n" ); document.write( "\n" ); document.write( "hence : equation is : 9x-3y=15 (which is just first equation, with the RHS
\n" ); document.write( "obtained by putting (x,y)=(1,-2) : 9-3*(-2)=15) \n" ); document.write( "

\n" );