Answer: The coefficient is 13.
Explanation:
Hi, to answer this question we have to know what a coefficient is first:
A coefficient is a number that multiplies a variable.
In this case in the expression 13a +6b, the variables are the letters "a" and "b", and the coefficients are the numbers 13 and 16.
But, if we only analyze the term 13a in the expression, the coefficient is 13.
Feel free to ask for more if needed or if you did not understand something.