I pretty sure the best answer would be f(x)=cbrt(27-x)
cbrt means cube root by the way.
Answer:
(a). $20,000
(b). The estimate will be lower than the actual amount.
Step-by-step explanation:
We have been given that Michael saves $423 dollars a month for college.
(a). We know that 1 year equals 12 months.
4 years = 4*12 months = 48 months.

Since we are asked to find the estimated amount of money Michael will save in 4 years, so we will estimate both quantities as:



Therefore, Michael will save approximately $20,000 in 4 years.
(b).
The estimate will be lower than the actual amount as we rounded $423 down $23 to nearest hundred that is $400 and rounded 48 up 2 to nearest ten that is 40.
Therefore, the estimate will be lower than the actual amount.
The answer to the question
First think out the equation, once you've done that multiply 3 by 25 to get 75