document.write( "Question 915932: helppp \r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( " Jen butler has been pricing Speed-Pass train fares for a group trip to New York.
\n" );
document.write( " three adults and four children must pay $129.
\n" );
document.write( " two adults and three children must pay $92.
\n" );
document.write( " Find the price of the adults ticket and the price of a child's ticket.
\n" );
document.write( " Adult
\n" );
document.write( " Child \n" );
document.write( "
Algebra.Com's Answer #555866 by josh_jordan(263)![]() ![]() You can put this solution on YOUR website! To solve, we need to set this word problem up as a system of linear equations. First, let's use the letter A to represent the Adult tickets and C to represent the child tickets. The problem says that 3 Adults and 4 children must pay 129 dollars. So,\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3A + 4C = 129\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next, we are told that 2 Adults and 3 children must pay 92 dollars. So,\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2A + 3C = 92\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Our system of equations are\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3A + 4C = 129 \n" ); document.write( "2A + 3C = 92\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We need to now solve for either A or C. Let's choose C. To solve for C, we need to multiply the first equation by a certain number, so that when we add that first equation to the second equation, our letter A will disappear. If we multiply equation 1 by -2 and the second equation by 3 and then add them together, our A will go away:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-2(3A + 4C = 129) -----> -6A - 8C = -258\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3(2A + 3C = 92) -----> 6A + 9C = 276\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now, let's add these two results together:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-6A - 8C + 6A + 9C = 276 - 258 -----> C = 18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now that we have solved for C, we can replace C in either of our two original equations with 18. Let's use equation 1:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3A + 4C = 129 -----> 3A + 4(18) = 129 -----> 3A + 72 = 129\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next, subtract both sides by 72:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3A + 72 - 72 = 129 - 72 -----> 3A = 57\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Finally, divide both sides by 3 to solve for A:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3A/3 = 57/3 -----> A = 19\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore, the price of an Adult ticket is $19 and the price of a Child ticket is $18.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |