document.write( "Question 63604: Can you please help me solve using the substitution method?
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\n" ); document.write( "x + 7y = 16
\n" ); document.write( "-3x + 6y = 33 \n" ); document.write( "
Algebra.Com's Answer #44414 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
In the 1st equation we can see that x has a coefficient of 1 so let's arrange
\n" ); document.write( "the equation, so we substitute for x:
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\n" ); document.write( "x + 7y = 16
\n" ); document.write( "x = (16 - 7y)
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\n" ); document.write( "-3x + 6y = 33
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\n" ); document.write( "Substitute (16-7y) for x in the 2nd equation:
\n" ); document.write( "-3(16-7y) + 6y = 33
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\n" ); document.write( "Multiply what is inside the brackets by -3:
\n" ); document.write( "-48 + 21y + 6y = 33
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\n" ); document.write( "Add 48 to both sides:
\n" ); document.write( "21y + 6y = 33 + 48
\n" ); document.write( "27y = 81
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\n" ); document.write( "Divide both sides by 27:
\n" ); document.write( "y = 81/27
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\n" ); document.write( "y = +3
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\n" ); document.write( "Find x, substitute 3 for y in the 1st equation:
\n" ); document.write( "x + 7(3) = 16
\n" ); document.write( "x + 21 = 16
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\n" ); document.write( "Subtract 21 from both sides:
\n" ); document.write( "x = 16 - 21
\n" ); document.write( "x = -5
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\n" ); document.write( "Check solutions in 2nd equation:
\n" ); document.write( "-3(-5) + 6(3) = 33
\n" ); document.write( "+15 + 18 = 33 proves our solutions are correct
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\n" ); document.write( "Can you do this now?
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