document.write( "Question 251998: please help me solve: 2x-2y=4 and 3y-x=1 \n" ); document.write( "
Algebra.Com's Answer #183732 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
equations are:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2x - 2y = 4
\n" ); document.write( "3y - x = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "presumably you want to solve them simultaneously.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "use the second equation to solve for y in terms of x and then use that value to substitute in the first equation to solve for x.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "second equation is:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3y - x = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "add x to both sides and subtract 1 from both sides to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3y - 1 = x\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "take the value of x in terms of y and substitute in the first equation.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "first equation is:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2x - 2y = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "substitute 3y-1 for x to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2*(3y-1) - 2y = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "simplify by performing indicated operatioons to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "6y - 2 - 2y = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "combine like terms to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4y - 2 = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "add 2 to both sides of equation to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4y = 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "divide both sides of equation by 4 to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = (6/4)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "substitute for y in the second equation and solve for x.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "second equation is:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3y - x = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "replace y with (6/4) to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3*(6/4) - x = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "simplify by performing indicated operations to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(18/4) - x = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "add x to both sides of this equation and subtract 1 from both sides of this equation to get\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(18/4) - 1 = x\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "simplify to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = (14/4)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "you have:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = (14/4)
\n" ); document.write( "y = (6/4)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "substitute in both equations to confirm these values will solve both equations (both equations will be true)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "your equations are:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2x - 2y = 4
\n" ); document.write( "3y - x = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "these equations becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2*(14/4) - 2*(6/4) = 4
\n" ); document.write( "3*(6/4) - (14/4) = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "simplifying, these equations become:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "28/4 - 12/4 = 4
\n" ); document.write( "18/4 - 14/4 = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "simplifying further, these equations become:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "16/4 = 4
\n" ); document.write( "4/4 = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "both these equations are true, so the values for x and y are good.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = (14/4)
\n" ); document.write( "y = (6/4)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "these answers are the same as:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = 3.5
\n" ); document.write( "y = 1.5\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );