document.write( "Question 285793: The sum of three numbers is 98. The first number is 2/3 of the second, and the second is 5/8 of the third. What is the second number?\r
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document.write( "A. 18 B. 20 C. 30 D. 48 E. None of these. \n" );
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Algebra.Com's Answer #207208 by Theo(13342)![]() ![]() You can put this solution on YOUR website! Sum of 3 number is 98. \n" ); document.write( "x = first number \n" ); document.write( "y = second number \n" ); document.write( "z = third number\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = (2/3)*y\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = (5/8)*z\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x + y + z = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since y = (5/8) * z, the equation becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x + (5/8)*z + z = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since x = (2/3) * y, and y = (5/8) * z, this means that:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = (2/3)*(5/8)*z.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute that value into the equation, and the equation becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(2/3)*(5/8)*z + (5/8)*z + z = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You can factor out the z to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z * ((2/3)*(5/8) + (5/8) + 1) = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Simplify this equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z * ((10/24) + (5/8) + (8/8)) = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Simplify further to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z * ((10/24) + (15/24) + (24/24)) = 98\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( "z * (49/24) = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Divide both sides of this equation by (49/24) to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z = 98 / (49/24) which is the same as:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z = 98 * (24/49).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Simplify this to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z = 2*24 = 48\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since z = 48, and y = (5/8)*z, this means that y = (5/8)*48 = 5*6 = 30.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You have:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z = 48 \n" ); document.write( "y = 30\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since y = 30, and x = (2/3)*y, this means that x = (2/3)*30 = 20.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You have:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "z = 48 \n" ); document.write( "y = 30 \n" ); document.write( "x = 20\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "To confirm these are accurate, substitute in your original equation to see if that equation is true using these values.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Your original equation is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x + y + z = 98\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "That becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "20 + 30 + 48 = 98 which becomes 98 = 98 which is true.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "These values are good for the sum equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute in the piece part equations to see if they still hold up.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The first piece part is x = 2/3 * y.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since 20 = 2/3 * 30 is true, this part is good.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The second piece part is y = (5/8) * z.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since 30 = 5/8 * 48, this part is also good.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The solutions of:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 20 \n" ); document.write( "y = 30 \n" ); document.write( "z = 48\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "are all good.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The answer to your question is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The second number is 30.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "That would be selection C.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |