For the arithmetic sequence
a₁, a₂, a₃, ...,
The n-th term is

where d = common difference.
Because a₁₀ = 41,
a₁ + 9d = 41 (1)
Because a₁₅ = 61
a₁ + 14d = 61 (2)
Subtract (1) from (2).
5d = 20
d = 4
From (1), obtain
a₁ = 41 - 9*4 = 5
Therefore
a₃ = 5 + 2*4 = 13
Answer: a₃ = 13
Answer:
id c hot hf hdjhdw fhwjfehf v;e
Step-by-step explanation:
id c h
A) 2in:80 mi
B) 3.5in:120mi
C) 4.75:190mi
Answer:
4,5 miles
Step-by-step explanation:
In 1 hour: 18/3 = 6 miles
6 . 3/4 = 18/4 = 4,5 miles