document.write( "Question 532409: The sum of three numbers is 18. The sum of the first and second numbers is 15. The first number is 3 times larger than the third number. Solve for the three variables \n" ); document.write( "
Algebra.Com's Answer #350840 by Maths68(1474)\"\" \"About 
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Let
\n" ); document.write( "Third Number = x
\n" ); document.write( "Second Number = y
\n" ); document.write( "First Number = 3x \r
\n" ); document.write( "\n" ); document.write( "The sum of 3 numbers is 18
\n" ); document.write( "x+3x+y=18
\n" ); document.write( "4x+y=18............(1)
\n" ); document.write( "The sum of the first two numbers is 15
\n" ); document.write( "3x+y=15..............(2)
\n" ); document.write( "Take (2)
\n" ); document.write( "3x+y=15
\n" ); document.write( "y=15-3x.........(3)
\n" ); document.write( "Put the value of y in (1)
\n" ); document.write( "4x+y=18
\n" ); document.write( "4x+(15-3x)=18
\n" ); document.write( "4x+15-3x=18
\n" ); document.write( "x=18-15
\n" ); document.write( "x=3
\n" ); document.write( "Put the value of x in (2)
\n" ); document.write( "3x+y=15
\n" ); document.write( "3(3)+y=15
\n" ); document.write( "9+y=15
\n" ); document.write( "y=15-9
\n" ); document.write( "y=6 \r
\n" ); document.write( "\n" ); document.write( "Third Number = x = 3
\n" ); document.write( "Second Number = y = 6
\n" ); document.write( "First Number = 3x = 3(3) = 9 \n" ); document.write( "
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