Answer:
a₁ = -5, d = 7, a₂ = 2, a₃ = 9, a₄ = 16
equation of sequence: 
Step-by-step explanation:
a₁ + a₂ + a₃ = 6
a₁ + a₁ + d + a₁ + 2d = 6
3a₁ + 3d = 6
a₁ + d= 2 ⇒ a₁ = 2 - d
a₄ = 16
a₁ + 3d = 16
2 - r + 3d = 16
2d = 14
d = 7
a₁ = 2-7 = -5
a₁ = -5, d = 7 ⇒ a₂ = -5+7 = 2, a₃ = 2+7 = 9, a₄ = 9+7 = 16
equation of arithmetic sequence:

We can use the arc length formula to solve this.
Arc length = 
Given arc length is 7 and radius is 5, we can plug in the values and solve for q.

ANSWER:
We can use the equation
to find the value of q. And, the value of q is 80.21°.
Answer:
40
Step-by-step explanation:
Let number of stickers Sophia has be "x" and number of stickers Ethan has be "y"
Now,
Sophia has 3 for every 2 ethan has, that means
3x = 2y
When sophia gives 16, she will have:
3x - 16
Ethan, after getting 16, will have:
2y + 16
This trade will make Ethan to have TWICE, so we can write:
2(3x-16) = 2y + 16
Now, the 1st equation can be written as:
3x = 2y
x = 2y/3
Now replacing this into 2nd, we solve for y:
So altogether they have:
24+16=40