Answer: Option D.
Explanation:
You know that the expression given in the exercise represents the cost a custom pays for an item. This is:
As you can see, the expression has two terms, and the variable is the cost c.
The variable of the first term is c and the coefficient is 1.
The variable of the second term is c and the coefficient is 0.85
As both are like terms, you can add the coefficients. Therefore, you obtain the following equivalent expression:
