n(n+1)
Looks like 57: 12+9=21, +9=30, +9=39, +9=48, +9=57.
here t1=2 t2=6 t3=12 t4=20 t5=30 the nth term is n(n+1) for t1 = 1(1+1)=2 for t2=2(2+1)=6 for t3=3(3+1)=12 for t4=4(4+1)=20 for t5=5(5+1)=30 for tn=n(n+1)
6n+10
When n=30, 3n-1 = 89 .
n(n+1)
> since the value rises by nine at each step and the first term is 12 the formula for > the nth term is: 12+(n-1)*9 Which simplifies to Sn = 9n + 3
Clearly here the nth term isn't n25.
90
Looks like 57: 12+9=21, +9=30, +9=39, +9=48, +9=57.
here t1=2 t2=6 t3=12 t4=20 t5=30 the nth term is n(n+1) for t1 = 1(1+1)=2 for t2=2(2+1)=6 for t3=3(3+1)=12 for t4=4(4+1)=20 for t5=5(5+1)=30 for tn=n(n+1)
6n+10
When n=30, 3n-1 = 89 .
The difference between the terms increases by 2 each time. 20-12=8 30-20=10 42-30=12 56-42=14 ... f(n)=(n+2)(n+3)
The nth term is 7n-5 and so the 6th term will be 37
Just plug in 30 for n in 3n-1. The answer is 89.
3 x 10(n-1)