Question

11. Determine the A.P whose nth term is 8-5n hence; find the sum of 25 terms.

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Answer 1

I think this could be the write answer

Answer 2

hey mate!

here is your answer:

step by step explanation:

nth term = 8-5n

so, 1st term (a) = 8-5(1)=8-5=3

2nd term (a+d) = 8-5(2)=8-10=-2

d = 2nd term - 1st term

d = -2 -3=-5

Now, sum of 25 terms = n/2[2a+(n-1)d]

= 25/2[6+(24)-5]

=25/2[6-120]

=25/2[-114]

=25×-57

=-1425

hope it helped^_^