Obviously this isn't me presenting this, but this is a very clear and concise video on how to do this: http://www.virtualnerd.com/pre-algebra/factors-fractions-exponents/prime-factorization-greatest-common-factor/greatest-common-factor/greatest-common-factor-monomials   To put it...

No matter what, it will cost 174.20 per month for insurance and payment.  Whether you drive the car 1 mile, or 1000 miles, you will pay 174.20 per month for this.  That makes 174.20 your "constant" figure.  Miles driven can vary month to month, so this will be your variable...

Think of the smallest prime number that 272 can be divided by, then divide it by that number.  Since prime numbers can only be divided by themselves and 1, you don't have to worry about simplifying the number you divided by.  Replace 272 with the answer you got when you divided, and repeat...

In the first two questions, you need to find out how much each company charges for the number of hours of work.  Then you can add any extra fees on top of what your answer for each company is.  Whichever company you can get the cheapest would be the better deal. For the third question,...