1. The problem statement, all variables and given/known data This is a limit problem but what I'm stuck on is algebra: find lim as u approaches 1 of ((u^4)-1)/((u^3)-1). 2. Relevant equations 3. The attempt at a solution 1 is a root and (u-1) is a common factor, so I want to rearrange the numerator and denominator so I can cancel (u-1) in the hopes that it will leave an equation that does not have a zero denominator when I plug in 1 to find the limit. so the numerator either = ((u^2)-1)((u^2)+1) or (u-1)((u^3)+1) right? The denominator I'm not sure how to write so that it has a factor (u-1) and = (u^3)-1. Any help is appreciated!