document.write( "Question 1200591: If p=6q-r and t=3q+r , find p in terms of r and t .\r
\n" ); document.write( "\n" ); document.write( "What I did :
\n" ); document.write( "I first did r subject of formula:
\n" ); document.write( "3q+r=t
\n" ); document.write( "r=t-3q
\n" ); document.write( "Then I substituted the r in the other equation :
\n" ); document.write( "p=6q-(t-3q)
\n" ); document.write( "p=6q-t+3q
\n" ); document.write( "p=9q-t
\n" ); document.write( "But the correct answer is :p=2t-3r, how is this supposed to be worked out please? \n" ); document.write( "
Algebra.Com's Answer #834762 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
start with p = 6q - r and t = 3q + r
\n" ); document.write( "solve for q in both equations to get:
\n" ); document.write( "q = (p + r) / 6 and q = (t - r) / 3
\n" ); document.write( "since they are both equal to q, set them equal to each other to get:
\n" ); document.write( "(p + r) / 6 = (t - r) / 3
\n" ); document.write( "multiply both sides of the equation by 6 to get:
\n" ); document.write( "p + r = 2 * (t - r)
\n" ); document.write( "simplify to get:
\n" ); document.write( "p + r = 2t - 2r
\n" ); document.write( "subtract r from both sides of the equation to get:
\n" ); document.write( "p = 2t - 3r\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "you needed to eliminate q from the equations.
\n" ); document.write( "that was done by solving for q in both equations.
\n" ); document.write( "you then used what q was equivalent to in each equation rather than q itself.
\n" ); document.write( "that eliminated q from both equations and left p and t and r.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );