document.write( "Question 112100: Adult tickets for a play cost $8 and child tickets cost $6. If there were 25 people at a performance and the theater collected $188 from ticket sales, how many adults and how many children attended the play? \n" ); document.write( "
Algebra.Com's Answer #81801 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let x=# of adults, y=# of children\r
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\n" ); document.write( "\n" ); document.write( "Translate the following word problem:\r
\n" ); document.write( "\n" ); document.write( "\"x%2By=25\" \"If there were 25 people at a performance\"\r
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\n" ); document.write( "\n" ); document.write( "\"8x%2B6y=188\" \"Adult tickets for a play cost $8 and child tickets cost $6...the theater collected $188 from ticket sales\"\r
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Solved by pluggable solver: Solving a linear system of equations by subsitution

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\n" ); document.write( " Lets start with the given system of linear equations
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\n" ); document.write( " \"1%2Ax%2B1%2Ay=25\"
\n" ); document.write( " \"8%2Ax%2B6%2Ay=188\"
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\n" ); document.write( " Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to choose y.
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\n" ); document.write( " Solve for y for the first equation
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\n" ); document.write( " \"1%2Ay=25-1%2Ax\"Subtract \"1%2Ax\" from both sides
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\n" ); document.write( " \"y=%2825-1%2Ax%29\" Divide both sides by 1.
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\n" ); document.write( " Which breaks down and reduces to
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\n" ); document.write( " \"y=25-1%2Ax\" Now we've fully isolated y
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\n" ); document.write( " Since y equals \"25-1%2Ax\" we can substitute the expression \"25-1%2Ax\" into y of the 2nd equation. This will eliminate y so we can solve for x.
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\n" ); document.write( " \"8%2Ax%2B6%2Ahighlight%28%2825-1%2Ax%29%29=188\" Replace y with \"25-1%2Ax\". Since this eliminates y, we can now solve for x.
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\n" ); document.write( " \"8%2Ax%2B6%2A%2825%29%2B6%28-1%29x=188\" Distribute 6 to \"25-1%2Ax\"
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\n" ); document.write( " \"8%2Ax%2B150-6%2Ax=188\" Multiply
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\n" ); document.write( " \"8%2Ax%2B150-6%2Ax=188\" Reduce any fractions
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\n" ); document.write( " \"8%2Ax-6%2Ax=188-150\" Subtract \"150\" from both sides
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\n" ); document.write( " \"8%2Ax-6%2Ax=38\" Combine the terms on the right side
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\n" ); document.write( " \"2%2Ax=38\" Now combine the terms on the left side.
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\n" ); document.write( " \"cross%28%281%2F2%29%282%2F1%29%29x=%2838%2F1%29%281%2F2%29\" Multiply both sides by \"1%2F2\". This will cancel out \"2%2F1\" and isolate x
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\n" ); document.write( " So when we multiply \"38%2F1\" and \"1%2F2\" (and simplify) we get
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\n" ); document.write( " \"x=19\" <---------------------------------One answer
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\n" ); document.write( " Now that we know that \"x=19\", lets substitute that in for x to solve for y
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\n" ); document.write( " \"8%2819%29%2B6%2Ay=188\" Plug in \"x=19\" into the 2nd equation
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\n" ); document.write( " \"152%2B6%2Ay=188\" Multiply
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\n" ); document.write( " \"6%2Ay=188-152\"Subtract \"152\" from both sides
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\n" ); document.write( " \"6%2Ay=36\" Combine the terms on the right side
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\n" ); document.write( " \"cross%28%281%2F6%29%286%29%29%2Ay=%2836%2F1%29%281%2F6%29\" Multiply both sides by \"1%2F6\". This will cancel out 6 on the left side.
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\n" ); document.write( " \"y=36%2F6\" Multiply the terms on the right side
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\n" ); document.write( " \"y=6\" Reduce
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\n" ); document.write( " So this is the other answer
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\n" ); document.write( " \"y=6\"<---------------------------------Other answer
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\n" ); document.write( " So our solution is
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\n" ); document.write( " \"x=19\" and \"y=6\"
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\n" ); document.write( " which can also look like
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\n" ); document.write( " (\"19\",\"6\")
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\n" ); document.write( " Notice if we graph the equations (if you need help with graphing, check out this solver)
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\n" ); document.write( " \"1%2Ax%2B1%2Ay=25\"
\n" ); document.write( " \"8%2Ax%2B6%2Ay=188\"
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\n" ); document.write( " we get
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\n" ); document.write( " graph of \"1%2Ax%2B1%2Ay=25\" (red) and \"8%2Ax%2B6%2Ay=188\" (green) (hint: you may have to solve for y to graph these) intersecting at the blue circle.
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\n" ); document.write( " and we can see that the two equations intersect at (\"19\",\"6\"). This verifies our answer.
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\n" ); document.write( " Check:
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\n" ); document.write( " Plug in (\"19\",\"6\") into the system of equations
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\n" ); document.write( " Let \"x=19\" and \"y=6\". Now plug those values into the equation \"1%2Ax%2B1%2Ay=25\"
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\n" ); document.write( " \"1%2A%2819%29%2B1%2A%286%29=25\" Plug in \"x=19\" and \"y=6\"
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\n" ); document.write( " \"19%2B6=25\" Multiply
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\n" ); document.write( " \"25=25\" Add
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\n" ); document.write( " \"25=25\" Reduce. Since this equation is true the solution works.
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\n" ); document.write( " So the solution (\"19\",\"6\") satisfies \"1%2Ax%2B1%2Ay=25\"
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\n" ); document.write( " Let \"x=19\" and \"y=6\". Now plug those values into the equation \"8%2Ax%2B6%2Ay=188\"
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\n" ); document.write( " \"8%2A%2819%29%2B6%2A%286%29=188\" Plug in \"x=19\" and \"y=6\"
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\n" ); document.write( " \"152%2B36=188\" Multiply
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\n" ); document.write( " \"188=188\" Add
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\n" ); document.write( " \"188=188\" Reduce. Since this equation is true the solution works.
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\n" ); document.write( " So the solution (\"19\",\"6\") satisfies \"8%2Ax%2B6%2Ay=188\"
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\n" ); document.write( " Since the solution (\"19\",\"6\") satisfies the system of equations
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\n" ); document.write( " \"1%2Ax%2B1%2Ay=25\"
\n" ); document.write( " \"8%2Ax%2B6%2Ay=188\"
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\n" ); document.write( " this verifies our answer.
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\n" ); document.write( "\n" ); document.write( "So there were 19 adults and 6 children
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