The answer is the option C and the option D, which are:
C. Double the number of pages in the book.
D. The age of my friend.
The explanation for this problem is shown below:
By definition, a variable is an unkown quantity. In the Option A the quantity is given: 
seconds in a minute. In the option B you know the quantity too, which is 
years old. But the option C and the option D does not give any quantity, you don't know the number of pages in the book or the age of the friend yet. Therefore, the answer is the options C and D.
Answer:
4.2kg
Step-by-step explanation:
She feeds her dog .12 a day, so for a month, I would multiply by 30 or 31
(both will give you the same answer).
After doing that , you get 3.6 (I multiplied by 30)
The other 2 options are less than that.
Hope this helps!
Answer:
3
4
4
3
4
4
3
5
5
3
4
5
5
4848
Step-by-step explanation:
hope I helped
Mathematically written:
3 * x + 7 = 25
3x + 7 = 25
3x = 25 - 7
3x = 18
x = 18 / 3
x = 6
Proof:
3 * 6 + 7 = 25
18 + 7 = 25
25 = 25 → both sides of the equation are equal, our answer is correct
Notes:
A number - Is an unknown number, called a variable, which in this case is substituted by the letter x.
Hope it helped,
BioTeacher101
The correct answer is D
The equation of a circle is (x-h)^2 + (y-k)^2 = r^2
to find (h,k), you find the middle of the circle, in this scenario you do so by finding the middle of the diameter, a line that goes through the center of the circle.
To find the X value of the midpoint, add both x values together and divide by 2 and repeat for y
-13 + -1 = -14
-14/2 =-7
10+ -6 = 4
4/2 = 2
therefore (h,k) = ( -7, 2 )
Next plug these values in the equation of a circle
(x-h)^2 + (y-k)^2 = r^2
becomes
(x- (-7)) ^2 + (y-(2)) ^2 = r^2
to find r, use the distance formula to find the length of the diameter, 20, and divide by 2
plug 10 in for r and you get 100
(x+7)^2 + (y-2)^2 = 100
sorry for the late response
