Combine like terms -21a+16a

A)-5a ***
B)5a
C)37a
D)-37a
I'm not sure about this would someone tell me if it's right please 🙂

I agree.

because

(-21 + 16) a = -5 a

To combine like terms, you need to add or subtract the coefficients of variables that have the same variable term.

In the given expression, -21a and 16a are both terms with the variable "a". To combine them, add their coefficients:

-21a + 16a = -5a

Therefore, the correct answer is A) -5a.