Question

I wanted the answers to these questions...thanks is advance...and best luck for 10th exams

Answer 1

Ans 1 If 5th term is 0
Then a+4d = 0 or a=-4d ---------(1)
Now the the 33rd term is a+32d
or 28d -------- (from 1)
And now the 12th term is a+11d
Or 7d -------- (from 1)
Hence 33rd term is four times the 12th term...

Ans 2. 5th term of ap is a+4d
And 8th term is a+7d
Now, 5(a+4d)= 8(a+7d)
5a + 20d = 8a + 56d
3a = -36d
a = -12d
Or a+12d= 0 { which is the 13th term of the AP}
Hence proved........