Answer:
12x+18/x+5
Step-by-step explanation:
Let S be the sum,
S = 2 + 4 + 6 + ... + 2 (n - 2) + 2 (n - 1) + 2n
Reverse the order of terms:
S = 2n + 2 (n - 1) + 2 (n - 2) + ... + 6 + 4 + 2
Add up terms in the same positions, so that twice the sum is
2S = (2n + 2) + (2n + 2) + (2n + 2) + ... + (2n + 2)
or
2S = n (2n + 2)
Divide both sides by 2 to solve for S :
S = n (n + 1)
Answer:
The better but is 3 for $3.33
12 for $13.32
Step-by-step explanation:
3.33/3 = 1.11
2.68/2 = 1.34
The better buy is 3 for $3.33
1.11 x 12 = 13.32
1.34 x 12 = 16.08
