What are coefficients?

Coefficients are the numbers in front of variables.
Example:
In the term ##2x## 2 is the coefficient
In ##4x^5## the coefficient is the number 4
In the case where the term is given as a single letter for example ##y## the coefficient of the unknown is 1.
Let’s take a more complex term for example the quadratic equation
##x^2 + ##9x + 20
the coefficient would be 9 and the solution would be:
(##x + 4)(##x + 5)
as the two numbers 4 and 5 add to get the first number in this case 9 and multiply to give the second term in this case 20.