This week we learned about arithmetic sequences and arithmetic series. An example is listed with the whole process below:
In the question, Tn and T12 are required
First of all, in order to solve it, I need to figure out what is the difference(d) in the sequence. Secondly, I gathered all I need, I just bring the difference which is -5 and n which is 12 into the equation I can solve T12 which is -71. Last, same idea to find out Tn is just bring the difference -5 into the equation and Tn is solved which is -11- 5n.
I’m currently trying to memorize the equation that is included in the picture of the example by using it frequently in the practices.