OK , I have three questions I was a computer science student , so i am a bit confused about some terms . What is a variable x ? x is a quantity x is binary x is a point mass object x is digital logic x is electrons The other is when you try to find the "pairs of factors" of a number . You can either find its composite factor or prime factors . right ? I hope that is what it is really called , "pairs of composite factors" and "pairs of prime factors" Third one is when you try to solve a rational equation involving polynomials , you try to factor the polynomials in the numerator and the denominator , then find the LCM from the factors , right ? Can somebody give me an example of that ?