-0.75 is a rational number because it can be expressed as the fraction -3/4 and it is an integer
Answer:
Specific Learning Outcomes:
Solve problems that involve finding powers of a number
Description of mathematics:
In this problem students work with powers of numbers and, as a consequence, come to understand what is happening to the numbers.
Students also see how an apparently enormous and difficult calculation can be broken down into manageable parts. The students should come to realise that there are only a limited number of unit digits obtained when 7 is raised to a power. Further, these specific digits 'cycle round' as the power of 7 increases. This cycle is 7, 9, 3, 1, 7, 9, …
The same is true of the digit in the tens place.
The total cost that a customer should incur in its dealings with company A should be,
c = 50t + 100
For company B
c = 60t + 80
Equating these two charges
c = 50t + 100 = 60t + 80
Thus, the answer is the fourth choice.
