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

where d = the common difference
Because a₅ = 12.4,
a₁ + 4d = 12.4 (1)
Because a₉ = 22.4,
a₁ + 8d = 22.4 (2)
Subtract (1) from (2).
a₁ + 8d - (a₁ + 4d) = 22.4 - 12.4
4d = 10
d = 2.5
From (1),
a₁ = 12.4 - 4*2.5 = 2.4
Therefore
a₃₁ = 2.4 + 30*2.5 = 77.4
Answer: a₃₁ = 77.4
Plug -8 in for x:
4(-8) + 5
solve:
-32 + 5
-27
Divide 90 by 1.3 and you will get your answer.
Do it yourself! just follow instructions!
<3
Answer:
720 possible ways
Step-by-step explanation:
The gold is awarded to the first position, the silver is awarded to the second position while the bronze is awarded to the third position.
The first position can be taken by any of the 10 runners
Now, the second position can be taken by remaining 9 runners
while the third position can be taken by the renaming 8 runners.
Thus, the number of ways in which these medals can be awarded = 10 * 9 * 8 = 720 ways