document.write( "Question 147516: I had help with a previous question, and it was not a solvable problem. I need to see the steps on how the elimination process is done. Could you please help?
\n" ); document.write( "7r-4s=7
\n" ); document.write( "4r+7s=69
\n" ); document.write( "I need to solve using the elimination method. I think I need to solve for x, and use that answer in the 2nd equation. Your help is greatly apprecieated. \n" ); document.write( "
Algebra.Com's Answer #107890 by Alan3354(69443)\"\" \"About 
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7r-4s=7 eqn 1
\n" ); document.write( "4r+7s=69 eqn 2
\n" ); document.write( "This is 2 equations in 2 unknowns, r and s. You can solve for both r and s.
\n" ); document.write( "To eliminate one of the variables, you multiply both eqns by a number that will give the same coefficient for one of the variables. This is similar to finding the LCD, Least Common Denominator.
\n" ); document.write( "To eliminate the r terms, multiply eqn 1 by 4 and eqn 2 by 7.
\n" ); document.write( "----------
\n" ); document.write( "28r - 16s = 28
\n" ); document.write( "28r + 49s = 483
\n" ); document.write( "Subtract (2) from (1)
\n" ); document.write( "0r - 65s = -455
\n" ); document.write( "s = 7
\n" ); document.write( "----------
\n" ); document.write( "Substitute s into either eqn to find r.
\n" ); document.write( "7r -4*7 = 7
\n" ); document.write( "7r = 35
\n" ); document.write( "r = 5
\n" ); document.write( "----------
\n" ); document.write( "Check both eqns.
\n" ); document.write( "7*5 - 4*7 = 7 so eqn 1 is good.
\n" ); document.write( "4*5 + 7*7 = 69 so they both check.\r
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