Let Mia's score be

. Then, Erick scored 10 more than Mia, so his score is

. Isabelle scored 16 less than twice Mia's score, so her score is

. We can see that

is the sum of these variables, so
the expression represents the total of their scores in this scenario. Moreover, we recall that the variable in the expression,

,
represents Mia's score.To simplify this expression, we add up the variables and the numbers separately, giving us

. Therefore, in simplified form, the expression is equal to
4x - 6. The constant term
in an expression is the term not multiplied by a variable, so in this case, it is
-6.