With
, we have

Then the difference quotient is

since <em>h</em> ≠ 0.
Hello I hope this helps. I'm pretty sure this is the answer.
Part A: C
Part B: A
Answer : B x 1 2 3 4 y 3.2 6.4 9.6 12.8
WE analyze the first option A
x -- y -- Difference
8 -- 20
9 -- 22.5 -- 2.5
10 -- 25 -- 2.5
11 -- 27.5 -- 2.5
From the first function we can see there is a constant difference of 2.5.
We analyze the second option B
x -- y -- Difference
1 -- 3.2
2 -- 6.4 -- 3.2
3 -- 9.6 -- 3.2
48 -- 12.8 -- 3.2
From the second function we can see there is a constant difference of 3.2
3.2 is the greatest
So second function B has the greatest constant of variation.
The number will be itself when multiplied by 1.
The sum of twice and half the original number is 1, so the number is
2n +0.5n = 1
2.5n = 1
n = 1/2.5 = 0.4
The original number is 2/5.