Answer:
A) Reflection.
Step-by-step explanation:
From the figure shown, we can see that the blue triangle is flipped about the x-axis to form the red triangle.
When an object is flipped about a line, then this transformation is called reflection about that line.
Thus, we can say that reflection is taking place in the figure shown in which the x-axis is acting like a mirror. The blue triangle is the pre-image and the red triangle is the image after reflection.
The reflection about x-axis is given by:
We can check the co-ordinates of the triangles and confirm the the transformation occurring
Points of pre-image triangle:

Points of image triangle

Thus, the transformation is reflection.
I think maybe 3) would make the most sense because she wants a random sample of students and the other options are specific on the type of students.
She began with 20.
If she bought 7 more books and ended up with 17, that means she had ten beforehand. If she had half remaining, we simply double it, thus getting 20.
Answer:
Drink=5.75
Popcorn=1.83
Percentage for drink=75.9%
Step-by-step explanation
Let the popcorn be p
the drinks be d
6p+4d=34....(1)
12p+7d=66.25...(2)
Multiply (1) by 2
12p+8d=72....(3)
Substrate (2) from (3)
d=5.75
Substitute the value for d into (1)
6p+4(5.75)=34
6p+23=34
Substrate 23 from both sides
6p=11
Divide both sides by 6
p=1.83
So for one drink=$5.75
For one popcorn=$1.83
To determine the% for drink
5.75+1.83=7.58
5.75/7.58 ×100
575/7.58
75.858~75.9%
The percentage for drink is 75.9%
Answer:

Step-by-step explanation:
1) if the given sequence is 9;5;1;-3, then a₁=9; a₂=5; a₃=1 and a₄=-3 and
2) the difference is -4.
3) if the difference is -4, then the correct answer is A: aₙ=aₙ₋₁ - 4.