document.write( "Question 153084: For a school play, 340 tickets with a total value of $810 were sold. Some tickets cost $2 and some cost $3. How many of each type were sold? \n" ); document.write( "
Algebra.Com's Answer #112568 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let x=# of $2 tickets and y=# of $3 tickets \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "First translate the word problem into the system of equations:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"system%28x%2By=340%2C2x%2B3y=810%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let's use substitution to solve the system\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So let's isolate y in the first equation\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%2By=340\" Start with the first equation\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=340-x\" Subtract \"x\" from both sides\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-x%2B340\" Rearrange the equation\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "---------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since \"y=-x%2B340\", we can now replace each \"y\" in the second equation with \"-x%2B340\" to solve for \"x\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2x%2B3highlight%28%28-x%2B340%29%29=810\" Plug in \"y=-x%2B340\" into the first equation. In other words, replace each \"y\" with \"-x%2B340\". Notice we've eliminated the \"y\" variables. So we now have a simple equation with one unknown.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2x%2B%283%29%28-1%29x%2B%283%29%28340%29=810\" Distribute \"3\" to \"-x%2B340\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2x-3x%2B1020=810\" Multiply\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-x%2B1020=810\" Combine like terms on the left side\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-x=810-1020\"Subtract 1020 from both sides\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-x=-210\" Combine like terms on the right side\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=%28-210%29%2F%28-1%29\" Divide both sides by -1 to isolate x\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=210\" Divide\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-----------------First Answer------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the first part of our answer is: \"x=210\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since we know that \"x=210\" we can plug it into the equation \"y=-x%2B340\" (remember we previously solved for \"y\" in the first equation).\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-x%2B340\" Start with the equation where \"y\" was previously isolated.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-%28210%29%2B340\" Plug in \"x=210\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-210%2B340\" Multiply\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=130\" Combine like terms \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-----------------Second Answer------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the second part of our answer is: \"y=130\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-----------------Summary------------------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So our answers are:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=210\" and \"y=130\" which means that 210 $2 tickets and 130 $3 tickets were sold\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );