The set of natural numbers is {1, 2, 3, 4, ...} basically positive whole numbers
The set of whole numbers is {0, 1, 2, 3, ...} which is the set of natural numbers with 0 included
The set of integers is {..., -3, -2, -1, 0, 1, 2, 3, ...} consisting of positive and negative whole numbers, plus zero as well
The set of rational numbers is the set of all fractions of the form a/b where b is not equal to zero. Any whole number, natural number, and integer is also a rational number.
If the number cannot be expressed as a rational number, then it is said to be irrational
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With all that in mind, the answers are "integer" and "rational" as you wrote in the comment section above. The value -25 is in the set {..., -3, -2, -1, 0, 1, 2, 3, ...} which is the set of integers. So we can say that -25 is an integer.
-25 is not a whole number based on the definition I wrote above. The set of whole numbers I wrote above does not include any negative values. This is why -25 is not a natural number either.
We can say that -25 is rational since -25 = -25/1 which is a fraction of integers. Since -25 is rational, it cannot be irrational.
C - remember the vertical line test determines if something is a function. A function has 1 x value for 1 y value. A B and D have more than one y value for a given x value.
When solving for this problem, replace x with the first coordinate and solve. if the answer is what you have for the second, it is correct. The first number in an ordered pair is your x and the second is your y. So I would rewrite the equation like this and solve.
y=7x-19 y=7x+21
2=7(3)-19 9=7(4)-19 2=7(3)+21 9=7(4)+21
2=21-19 9=28-19 2=21+21 9=28+21
2=2 9=9 2=42 9=49
as you can see it is the first equation.
3x + 55 = 2(6x + 5)
3x + 55 = 12x + 10
9x = 45
x = 5
length of mid-segment = 6(5) + 5 = 35
Answer
A. 35.0