Answer: 
Step-by-step explanation:
In order to round to the nearest thousandth, you must observe the digit to the right of the digit in the thousandth place and then:
- If it is less than 5, you must round down.
- If it is greater than or equal than 5, you must round up.
In this case, given the number:

You can notice that the digit to the right of the digit in the thousandth place is 9.
Since
, you must round up. Then:

Finally, to express this as a single-digit times a power of ten, move the decimal point three places to the right. Then you get:

After the 15% discount, Maria pays 85% of the cost. That cost is the sum of the fixed cost and the variable (per visit) cost.
... (updated cost) = 0.85×($150 +$30×a)
... (updated cost) = 127.50 +25.50a . . . . in dollars
Answer:
its i think the first one and the last one
Step-by-step explanation:
sorry if its wrong but i think it is right