document.write( "Question 1017325: The sum of 2 times a first number and 4 times a second number is 78. If 1/2 the second number is subtracted from the first number, the result is 9. Find the number. \n" ); document.write( "

Algebra.Com's Answer #633641 by Cromlix(4381) $\"\"$ $\"About$

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Hi there,
\n" ); document.write( "Make First number = x
\n" ); document.write( "Second number = y
\n" ); document.write( "The sum of 2 times a first number
\n" ); document.write( "and 4 times a second number is 78
\n" ); document.write( "If 1/2 the second number is subtracted
\n" ); document.write( "from the first number, the result is 9.
\n" ); document.write( "2x + 4y = 78........(1)
\n" ); document.write( "x - y/2 = 9.........(2)
\n" ); document.write( "Multiply (2) by 2
\n" ); document.write( "2x + 4y = 78........(1)
\n" ); document.write( "2x - y = 18.........(2)
\n" ); document.write( "Subtract (2) from (1)
\n" ); document.write( " 5y = 60
\n" ); document.write( " y = 12
\n" ); document.write( "Substitute y = 12 into (1)
\n" ); document.write( "2x + 4y = 78
\n" ); document.write( "2x + 4(12) = 78
\n" ); document.write( "2x + 48 = 78
\n" ); document.write( "2x = 78 - 48
\n" ); document.write( "2x = 30
\n" ); document.write( "x = 15
\n" ); document.write( "First number = 15
\n" ); document.write( "Second number = 12
\n" ); document.write( "Hope this helps :-) \n" ); document.write( "

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