document.write( "Question 88741: Solve using system of equations (elimination method) show all work \n" ); document.write( "
Algebra.Com's Answer #64498 by malakumar_kos@yahoo.com(315)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( " Three oranges cost half of what nine apples cost. If one orange and one apple together cost 30 cents, how much does one orange cost?
\n" ); document.write( " Let the cost of 1 orange be = X cents and the cost of apple be = Y cents\r
\n" ); document.write( "\n" ); document.write( " total cost of 1 orange &1 apple = X+Y = 30 cents........eq'n (1)\r
\n" ); document.write( "\n" ); document.write( " given cost of 3 oranges = 1/2(cost of 9 apples)\r
\n" ); document.write( "\n" ); document.write( " i.e, 3X = 1/2(9Y)\r
\n" ); document.write( "\n" ); document.write( " X = 9Y/6 = 3Y/2 \r
\n" ); document.write( "\n" ); document.write( " eliminate X in eq'n (1) by substituting for X \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " therefore X+Y = 30, or 3Y/2+y = 30 \r
\n" ); document.write( "\n" ); document.write( " 3Y+2Y/2 = 30\r
\n" ); document.write( "\n" ); document.write( " 5Y/2 = 30\r
\n" ); document.write( "\n" ); document.write( " Y = 30*2/5 = 12\r
\n" ); document.write( "\n" ); document.write( " The cost of an apple = 12 cents\r
\n" ); document.write( "\n" ); document.write( " Therefore the cost of an orange = 30-12 = 18 cents\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );