Answer:
D. We can label the rational numbers with strings from the set (1, 2, 3, 4, 5, 6, 7, 8, 9, / -) by writing down the string that represents that rational number in its simplest form. As the labels are unique, it follows that the set of rational numbers is countable.
Step-by-step explanation:
The label numbers are rational if they are integers. The whole number subset is rational which is written by the string. The sets of numbers are represented in its simplest forms. The rational numbers then forms numbers sets which are countable.
Answer: The first table represents a function!
Step-by-step explanation:
Hope this helps!
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Answer:
hvfjbvhfvhacv,,,,,,,,,,sJvj
Step-by-step explanation:
Answer: The correct answer is B because 0.7x=210, x=300
Step-by-step explanation:
210= 70% of the total distance to his grandfather's house, lets take that total distance for x.
So if:
210=0.7x
x=210/0.7
x=300
well, we know the piece-wise function is 
hmmm so what's f(-1), namely what is f(x) when x = -1?
well, when x = -1, hmm -1 is less than 0, so the subfunction that applies to that will be when "x" is less than 0, namely the part of 7x + 10, so we can say
f(-1) = 7(-1) + 10
f(-1) = 3
so hmm what's f(0) or namely, what's f(x) when x = 0?
well, what subfunction applies when x = 0? well, it has to be the subfunction with "x greater or <u>equals</u> to 0", x ⩾ 0, so then is 7x + 20
f(0) = 7(0) + 20
f(0) = 20.