3. The first four terms of a sequence are: T2 = 12+ 22
T3 = 12 + 22 + 32
T4 = 12 + 22 + 32 +42
T1 = 12
The n" term is given by Tn=n(n + 1)(2n + 1).
Work out the value of T23.

The 23rd term is 2806.

Step-by-step explanation:

The other answerer has used the formula but i'm answering from the assumption that T1 to T4 are correct.

Each term is the sum of n terms of an arithmetic series with first term a1 = 12 and common difference d = 10.

Sum of n terms = (n/2)[2a1  + d(n - 1)]

So the sum of 23 terms =

= 23/2 (2*12 + 10 * 22)

= 11.5 * 244

= 2806.

there are 70 more legs than eyes at the dog show (196 – 126 = 70). dogs have two more legs than eyes, and humans have the same number of legs as eyes. thus 70 is twice the number of dogs at the show, so the number of dogs is half of 70, which is 35. to get the number of humans, subtract 35 from 63: 63 – 35 = 28.

step-by-step explanation: