document.write( "Question 161503: The sum of two numbers is 15. Three times one of the numbers is 11 less than 5 imes the other. The answer is 7 and 8. I just don't know how to set it up to solve. \n" ); document.write( "
Algebra.Com's Answer #118965 by gonzo(654)\"\" \"About 
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x = 1 of the numbers
\n" ); document.write( "y = the other number
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\n" ); document.write( "sum of the numbers equals 15 in equation form becomes
\n" ); document.write( "x + y = 15
\n" ); document.write( "three times one of the numbers equals 11 less than 5 times the other number in equation form becomes
\n" ); document.write( "3*x = 5*y - 11
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\n" ); document.write( "two equations to be solved simultaneously are:
\n" ); document.write( "x + y = 15
\n" ); document.write( "3*x = 5*y - 11
\n" ); document.write( "-----
\n" ); document.write( "in the second equation, subtract 5*y from both sides to get
\n" ); document.write( "3*x - 5*y = -11
\n" ); document.write( "equations are now both in the same form of a*x + b*y = c reproduced below.
\n" ); document.write( "x + y = 15
\n" ); document.write( "3*x - 5*y = -11
\n" ); document.write( "-----
\n" ); document.write( "multiply both sides of the first eqution by 3 to get
\n" ); document.write( "3*x + 3*y = 45
\n" ); document.write( "3*x - 5*y = -11
\n" ); document.write( "subtract the second equation from the first equation to get
\n" ); document.write( "0*x + 8*y = 56
\n" ); document.write( "effectively removing x from the equation to allow you to solve for y.
\n" ); document.write( "this becomes
\n" ); document.write( "8*y = 56
\n" ); document.write( "which becomes
\n" ); document.write( "y = 7
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\n" ); document.write( "original first equation is
\n" ); document.write( "x + y = 15
\n" ); document.write( "substituting 7 for y, we get
\n" ); document.write( "x + 7 = 15
\n" ); document.write( "subtracting 7 from both sides of the equation, we get
\n" ); document.write( "x = 15 - 7
\n" ); document.write( "which becomes
\n" ); document.write( "x = 8
\n" ); document.write( "-----
\n" ); document.write( "second original equation is
\n" ); document.write( "3*x = 5*y - 11
\n" ); document.write( "substituting 7 for y and 8 for x, we get
\n" ); document.write( "3*8 = 5*7 - 11
\n" ); document.write( "24 = 35 - 11
\n" ); document.write( "24 = 24
\n" ); document.write( "proving the values for x and y are correct.
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\n" ); document.write( "answers are:
\n" ); document.write( "x = 8
\n" ); document.write( "y = 7\r
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