Question

Rational Expression.

why can't we simplify x+1/x-1 to -1? please explain this thanks.

Answer 1

Because remembering that x represents a number if we plugged 5 in for both the top would be 5+1which equals 6 and the bottom would be 5-1 which equals 4 so essentially you would have 6/4. If the problem though was x+1/-(x+1) you could reduce it to -1. For example if we chose to plug 5 in we would get 6 on top again and -(6) on the bottom.