You just need to multiply the first number to the last. (a·c) In this case *a* is jus a positive 1. Then, you just find a product to the result you got from (a·c) that when it is added together the result is the same as the one you have as ¨b¨.
Also the sign betwee b and c tells you that if it is positive both of your products are going to have the same sign, and if it is negative it means that they are going to be different,(one negative and one positive). If the sign is positive then go to the sign between a and b, this tells you what sign your factors will have.
Know KHDBDCM. that's the order of prefixes. you start at Cent and move right once to Milli. So you move the decimal the same exact way in the number. So 2 centiliters is actually 20 milliliters.
