A) Divide total miles by total time:
21 miles / 4 hours = 5.25 miles per hour.
B) Divide miles by miles per hour:
42 miles / 5.25 miles per hour = 8 hours.
2[(9 - 5)^5/8] = 2[4^5/8] = 2[1024/8] = 2[128] = 256
Answer: first one is : the base salary of an employee and a 9% salary increase; second one is : the price of a winter coat and a 90% discount ; third one is : the number of students attending school last year and a 90% increase from last year ; fourth one is : the cost of groceries and a 9% discount with coupons
Step-by-step explanation:
Based on the calculations, the unknown number is equal to 
- Let the unknown number be x.
<h3>How to find an
unknown number:</h3>
Translate the word problem into an algebraic expression, we have;
Adding 21 to the unknown number:
Multiplying the result by 3:
84 more than two-thirds of the unknown number:
Equating the equations, we have:
Cross-multiplying, we have:
Read more on word problems here: brainly.com/question/13170908
