document.write( "Question 682728: I had the problem 18 - n = 21 and I found the answer doing this:
\n" ); document.write( "18 - n = 21
\n" ); document.write( "18 - n - 18 = 21 - 18
\n" ); document.write( "-n = 3
\n" ); document.write( "-1(-n) = -1(3)
\n" ); document.write( "n = -3
\n" ); document.write( "The thing I'm struggling with is justifying the steps like is that step distributive, associative, commutative etc.?
\n" ); document.write( "Thanks! \n" ); document.write( "

Algebra.Com's Answer #423306 by lynnlo(4176) $\"\"$ $\"About$

You can put this solution on YOUR website!
commutative \n" ); document.write( "

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