D) 30
A polygon can rotate a total of 360. This one has 12 sides and 12 angles that are all congruent. So to coincide with original image, it must rotate 1/12 of the way around
360/12=30
Answer: Option B
B. 
Step-by-step explanation:
We have the following equations:
(1)
(2)
Let us call "a" the coefficient of the variable x in the first equation and call "b" the coefficient of the variable x in the second equation.
Then we must multiply the number "a" by a value z such that when adding
the result is zero.

So

We solve the equation for z


The first equation must be multiplied by a value of 
Not sure hope you get the answer from someone else
Answer:
y= 4
Step-by-step explanation:
Answer:
The answer is c. 8 hours
Step-by-step explanation:
Since her battery dropped 25% in 2 hours then for it to drop 100% would take 8 hours.
25%+25%+25%+25%= 100%
so with this logic
25%= 2 hours
2+2+2+2=8
Hoped this helped !
Cheers, Z