Answer:
S₁₅ = 645
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
= 
[ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Using the nth term formula 
= 5n + 3 , then
a₁ = 5(1) + 3 = 5 + 3 = 8
a₂ = 5(2) + 3 = 10 + 3 = 13 , then
d = a₂ - a₁ = 13 - 8 = 5
Thus
S₁₅ = 
[ (2 × 8) + (14 × 5) ]
= 7.5( 16 + 70)
= 7.5 × 86
= 645
Emma’s statement makes sense and Charles’ doesn’t, bcuz when you say 0.75 it should be 75 tenths, because it’s less than a whole number, but charles said 7 and 5 tenths, if it’s 7 and 5 tenths, it would be 7.5.
The box was filled with exactly 125 unit cubes because volume means it has to be filled.
Hope this helps! <span>＼(≧▽≦)／</span>
This is the Internet. It's really easy to look up.
Answer:
population = 5652 people
Step-by-step explanation:
area = πr² = (3.14)(6²) = 113.04 mi²
at 50 people/mi², then 113.04 x 50 = 5652 people
