An= mth term.
an=a₁+(n-1)*d
a₁₂=41
a₁₅=140
a₁₂=41
41=a₁+(12-1)*d
41=a₁+11d
a₁+11d=41 (1)
a₁₅=140
140=a₁+(15-1)*d
140=a₁+14d
a₁+14d=140 (2)
With the equiations (1) and (2) build a system of equations
a₁+11d=41
a₁+14d=140
we solve it.
-(a₁+11d=41)
a₁+14d=140
--------------------
3d=99 ⇒d=99/3=33
a₁+11d=41
a₁+(11*33)=41
a₁+363=41
a₁=41-363=-322
an=a₁+(n-1)*d
an=-322+(n-1)*33
an=-322+33n-33
an=-355+33n
an=-355+33n
To check:
a₁₂=-355+33*12=-355+396=41
a₁₅=-355+33*15=-355+495=140.
<span>Given that the orbital period, P, of a planet and the planet’s distance from the sun, a, in astronomical units is related by the formula P = a^(3/2).
If Saturn’s orbital period is 29.5 years, then
29.5 = a^(3/2)
a = (29.5)^(2/3) = 9.547
Therefore, Saturn's distance from the sun is 9.547 astronomical units.</span>
Based on the information given, the speed is 20 miles per hour.
From the information given, the winner of the local triathlon swam 0.5 miles, biked 15 miles and ran 2.5 miles and he finished the race in 54 minutes.
Note that 54 minutes = 0.9 hour.
The speed will be:
= (0.5 + 15 + 2.5) / 0.9
= 18/0.9
= 20 miles per hour.
Learn more about speed on:
brainly.com/question/4931057
