document.write( "Question 557102: the measurement of angle 1 =2x+40
\n" ); document.write( "the measurement of angle 2 =2y+40
\n" ); document.write( "the measurement of angle 3 =x+2y
\n" ); document.write( "And there is a picture that looks roughly like this:
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Algebra.Com's Answer #362452 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
Angles 1 and 3 are vertical to each other; angle 2 is supplementary to 1 and to 3.
\n" ); document.write( "\"2x%2B40=x%2B2y\" (angles 1 and 3 have the same measure)
\n" ); document.write( "\"%282x%2B40%29%2B%282y%2B40%29=180\" (measures of angles 1 and 2 add to 180°)
\n" ); document.write( "\"%282y%2B40%29%2B%28x%2B2y%29=180\" (measures of angles 2 and 3 add to 180°)
\n" ); document.write( "That gives you 3 equations on 2 variables.
\n" ); document.write( "Let's simplify:
\n" ); document.write( "\"2x%2B40=x%2B2y\" --> \"x-2y=-40\"
\n" ); document.write( "\"%282x%2B40%29%2B%282y%2B40%29=180\" --> \"2x%2B2y%2B80=180\" --> \"2x%2B2y=100\" --> \"x%2By=50\"
\n" ); document.write( "\"%282y%2B40%29%2B%28x%2B2y%29=180\" --> \"x%2B4y%2B40=180\" --> \"x%2B4y=140\"
\n" ); document.write( "With two of the equations we may find a solution, which we would need to substitute in the other equation to see that it verifies.
\n" ); document.write( "If we take the system
\n" ); document.write( "\"x%2By=50\"
\n" ); document.write( "\"x%2B4y=140\"
\n" ); document.write( "subtracting the first equation from the second, we get
\n" ); document.write( "\"3y=90\" --> \"y=30\"
\n" ); document.write( "and substituting into the first equation we get
\n" ); document.write( "\"x%2B30=50\" --> \"x=20\"
\n" ); document.write( "If \"x=20\" with \"y=30\" satisfies \"x-2y=-40\", then (x,y)=(20,30) is the solution. If not, there is no solution.
\n" ); document.write( "With \"x=20\" and \"y=30\", \"x-2y=20-2%2A30=20-60=-40\", so (20,30)
\n" ); document.write( "(or \"x=20\" with \"y=30\" ) is the solution.
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