They are any number in front of a variable so like 4x 7y or 8z. 4, 7 and 8 are the coefficients. A number by itself is a constant. For example 3, 1 and 9 are constants.
Coefficients are the numbers beside a variable. They are what the variable is multiplied by. Examples are the 12 in 12x or the 4 in 4a.
-About common core, lucky. Common core is absolutely unnecessary and only prepared me for geometry proofs. I don't know if that is the common core version of coefficients or not, but it wasn't confusing to me so it probably wasn't common core.
