document.write( "Question 101732: y=2x+5
\n" ); document.write( "3x-y=4\r
\n" ); document.write( "\n" ); document.write( "page 69 algebra review \n" ); document.write( "
Algebra.Com's Answer #73984 by doukungfoo(195)\"\" \"About 
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There are three ways to solve systems of equations with two variables.
\n" ); document.write( "They are
\n" ); document.write( "1. Substitution Method
\n" ); document.write( "2. Elimination Method
\n" ); document.write( "3. Graphing\r
\n" ); document.write( "\n" ); document.write( "For this problem I will demonstrate the substitution method.
\n" ); document.write( "Ok so we are working with two equations:
\n" ); document.write( "y = 2x + 5
\n" ); document.write( "3x - y = 4\r
\n" ); document.write( "\n" ); document.write( "The first equation shows that 2x+5 equals y So we are going to take 2x+5 and substitute it for y in the second equation. So you can see that is why this is called the substitution method.
\n" ); document.write( "ok we have
\n" ); document.write( "3x - y = 4
\n" ); document.write( "now substitute y with 2x+5
\n" ); document.write( "3x - (2x + 5) = 4
\n" ); document.write( "now we can solve for x
\n" ); document.write( "first distribute the negative sign across (2x + 5)
\n" ); document.write( "3x - 2x - 5 = 4
\n" ); document.write( "next combine like terms
\n" ); document.write( "x - 5 = 4
\n" ); document.write( "now solve for x by adding 5 to both sides
\n" ); document.write( "x = 9
\n" ); document.write( "ok we found our first variable x = 9
\n" ); document.write( "now use this value for x and substitute it in the first equation.
\n" ); document.write( "and solve for y\r
\n" ); document.write( "\n" ); document.write( "y = 2x + 5
\n" ); document.write( "y = 2(9) + 5
\n" ); document.write( "y = 18 + 5
\n" ); document.write( "y = 23
\n" ); document.write( "now we have found the second variable y = 23
\n" ); document.write( "All that is left to do is check our answers.
\n" ); document.write( "y = 2x + 5
\n" ); document.write( "23 = 2(9) + 5
\n" ); document.write( "23 = 18 + 5
\n" ); document.write( "23 = 23
\n" ); document.write( "now check the answers in the second equation
\n" ); document.write( "3x - y = 4
\n" ); document.write( "3(9) - 23 = 4
\n" ); document.write( "27 - 23 = 4
\n" ); document.write( "4 = 4
\n" ); document.write( "So the answers we got work for both equations.
\n" ); document.write( "Thats it.\r
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