document.write( "Question 112249: I need help on this word problem. Thank You in advance for your help.\r
\n" ); document.write( "\n" ); document.write( "Adult tickets for a play cost $8 and child tickets cost $1. If there were 22 people at a performance and the theater collected $50, how many children attended the play?
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Algebra.Com's Answer #81886 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let x=# of adult tickets, y=# of child tickets\r
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\n" ); document.write( "\n" ); document.write( "Translate the following word problem:\r
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\n" ); document.write( "\n" ); document.write( "\"If there were 22 people at a performance\"----> \"x%2By=22\"\r
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\n" ); document.write( "\n" ); document.write( "\"dult tickets for a play cost $8 and child tickets cost $1...the theater collected $50\"---->\"8x%2By=50\"\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=22\"
\n" ); document.write( " \"8%2Ax%2B1%2Ay=50\"
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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=22-1%2Ax\"Subtract \"1%2Ax\" from both sides
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\n" ); document.write( " \"y=%2822-1%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=22-1%2Ax\" Now we've fully isolated y
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\n" ); document.write( " Since y equals \"22-1%2Ax\" we can substitute the expression \"22-1%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%2B1%2Ahighlight%28%2822-1%2Ax%29%29=50\" Replace y with \"22-1%2Ax\". Since this eliminates y, we can now solve for x.
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\n" ); document.write( " \"8%2Ax%2B1%2A%2822%29%2B1%28-1%29x=50\" Distribute 1 to \"22-1%2Ax\"
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\n" ); document.write( " \"8%2Ax%2B22-1%2Ax=50\" Multiply
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\n" ); document.write( " \"8%2Ax%2B22-1%2Ax=50\" Reduce any fractions
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\n" ); document.write( " \"8%2Ax-1%2Ax=50-22\" Subtract \"22\" from both sides
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\n" ); document.write( " \"8%2Ax-1%2Ax=28\" Combine the terms on the right side
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\n" ); document.write( " \"7%2Ax=28\" Now combine the terms on the left side.
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\n" ); document.write( " \"cross%28%281%2F7%29%287%2F1%29%29x=%2828%2F1%29%281%2F7%29\" Multiply both sides by \"1%2F7\". This will cancel out \"7%2F1\" and isolate x
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\n" ); document.write( " So when we multiply \"28%2F1\" and \"1%2F7\" (and simplify) we get
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\n" ); document.write( " \"x=4\" <---------------------------------One answer
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\n" ); document.write( " Now that we know that \"x=4\", lets substitute that in for x to solve for y
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\n" ); document.write( " \"8%284%29%2B1%2Ay=50\" Plug in \"x=4\" into the 2nd equation
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\n" ); document.write( " \"32%2B1%2Ay=50\" Multiply
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\n" ); document.write( " \"1%2Ay=50-32\"Subtract \"32\" from both sides
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\n" ); document.write( " \"1%2Ay=18\" Combine the terms on the right side
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\n" ); document.write( " \"cross%28%281%2F1%29%281%29%29%2Ay=%2818%2F1%29%281%2F1%29\" Multiply both sides by \"1%2F1\". This will cancel out 1 on the left side.
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\n" ); document.write( " \"y=18%2F1\" Multiply the terms on the right side
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\n" ); document.write( " \"y=18\" Reduce
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\n" ); document.write( " So this is the other answer
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\n" ); document.write( " \"y=18\"<---------------------------------Other answer
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\n" ); document.write( " So our solution is
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\n" ); document.write( " \"x=4\" and \"y=18\"
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\n" ); document.write( " which can also look like
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\n" ); document.write( " (\"4\",\"18\")
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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=22\"
\n" ); document.write( " \"8%2Ax%2B1%2Ay=50\"
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\n" ); document.write( " we get
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\n" ); document.write( " graph of \"1%2Ax%2B1%2Ay=22\" (red) and \"8%2Ax%2B1%2Ay=50\" (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 (\"4\",\"18\"). This verifies our answer.
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\n" ); document.write( " Check:
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\n" ); document.write( " Plug in (\"4\",\"18\") into the system of equations
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\n" ); document.write( " Let \"x=4\" and \"y=18\". Now plug those values into the equation \"1%2Ax%2B1%2Ay=22\"
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\n" ); document.write( " \"1%2A%284%29%2B1%2A%2818%29=22\" Plug in \"x=4\" and \"y=18\"
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\n" ); document.write( "
\n" ); document.write( " \"4%2B18=22\" Multiply
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\n" ); document.write( " \"22=22\" Add
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\n" ); document.write( " \"22=22\" Reduce. Since this equation is true the solution works.
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\n" ); document.write( " So the solution (\"4\",\"18\") satisfies \"1%2Ax%2B1%2Ay=22\"
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\n" ); document.write( "
\n" ); document.write( " Let \"x=4\" and \"y=18\". Now plug those values into the equation \"8%2Ax%2B1%2Ay=50\"
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\n" ); document.write( " \"8%2A%284%29%2B1%2A%2818%29=50\" Plug in \"x=4\" and \"y=18\"
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\n" ); document.write( "
\n" ); document.write( " \"32%2B18=50\" Multiply
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\n" ); document.write( " \"50=50\" Add
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\n" ); document.write( "
\n" ); document.write( " \"50=50\" Reduce. Since this equation is true the solution works.
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\n" ); document.write( "
\n" ); document.write( " So the solution (\"4\",\"18\") satisfies \"8%2Ax%2B1%2Ay=50\"
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\n" ); document.write( " Since the solution (\"4\",\"18\") satisfies the system of equations
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\n" ); document.write( " \"1%2Ax%2B1%2Ay=22\"
\n" ); document.write( " \"8%2Ax%2B1%2Ay=50\"
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\n" ); document.write( " this verifies our answer.
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\n" ); document.write( "\n" ); document.write( "So there were 4 adults and 18 children
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