Final answer:
The term that describes both 19x and 4x in the expression 19x+4x is 'term'.
Step-by-step explanation:
The term that describes both 19x and 4x in the expression 19x+4x is term. In a mathematical expression, a term is a single number or variable, or a combination of both, that are separated by addition or subtraction. In this case, 19x and 4x are both terms because they are separate parts of the expression.