Question 198381
{{{(x-1)((x-4)/(x^2-1))}}} Start with the given expression.



{{{(x-1)((x-4)/((x-1)(x+1)))}}} Factor the denominator



{{{((x-1)(x-4))/((x-1)(x+1))}}} Combine the terms.



{{{(cross((x-1))(x-4))/(cross((x-1))(x+1))}}} Cancel out the common terms.



{{{(x-4)/(x+1)}}} Simplify



So {{{(x-1)*((x-4)/(x^2-1))=(x-4)/(x+1)}}}