Determine the general formula and then calculate T10, T15 and T30 for the following sequences:
−21;−27;−33;−39;−45;…
The general formula for this sequence is Tn = -6n - 15.
Calculating T10:
T10 = -6(10) - 15
T10 = -60 - 15
T10 = -75
Calculating T15:
T15 = -6(15) - 15
T15 = -90 - 15
T15 = -105
Calculating T30:
T30 = -6(30) - 15
T30 = -180 - 15
T30 = -195
Therefore, T10 = -75, T15 = -105, and T30 = -195.