document.write( "Question 935113: Is (R-{0},*) a group, how to prove it...
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #568227 by rothauserc(4718)\"\" \"About 
You can put this solution on YOUR website!
Consider, (R*,*) where R* = R - {0} IS a group.
\n" ); document.write( "multiplication in R is associative, so remains associative on any subset of R.
\n" ); document.write( "the product of two non-zero real numbers is again a non-zero real number, R* is closed under multiplication.
\n" ); document.write( "1 functions as a multiplicative identity:
\n" ); document.write( "for any NON-ZERO real number a, a*1 = 1*a = a.
\n" ); document.write( "any non-zero real number a has a (unique) inverse, 1/a, with
\n" ); document.write( "a*(1/a) = (1/a)*a = 1.
\n" ); document.write( "
\n" );