Brianna's thinking is incorrect.
Expessions A, and C. are equivalent.
For C, you add 5x and x together (because they have the same variable) to get 6x - 4.
For A, you subtract 9x and 3x (because they have the same variable) to get 6x- 4.
Answer:
x = 1 ; x = -7/2
Step-by-step explanation:

Here the sol. of x =
1) x - 1 = 0
=> x = 1
2) 2x + 7 = 0
=> 2x = -7
=> x = -7/2
Answer:
26.4° (nearest tenth)
Step-by-step explanation:


<em>Taking the inverse of sine on both sides:</em>

x= 26.4° (nearest tenth)
Each of these questions is substantially the same as the others. The answer is, "it depends" on what you want a random sample of. If you want random people in the country, you will not get that from these protocols.
If you want random people that meet certain criteria (have phones, shop in eyeglasses stores, use specific venues), then these protocols will deliver.