Question

howmany term are in each séquence
a). 39,36,33,- - - - - - -,-18​

Answer 1

Answer:

a = first term = 39

common difference (d) = 36 - 39 = (-3)

Let -18 be the nth term of the arothmwtic progression(sequence)

nth term = a + (n - 1)d

So, - 18 = 39 + (n - 1)(-3)

-18 - 39 = -3n + 3

-3n + 3 = -57

-3n = -57 -3 = -60

n = -60/-3 = 20

So, -18 is the 20th term of the sequence.

Therefore, there are 20 terms in the sequence.

Answer 2

Answer:

first term,a=39

common difference,d=36-39=-3

last term,an=-18

an=a+(n-1)d

-18=39+(n-1)-3

-18-39=(n-1)-3

-57=-3(n-1)

-57/-3=n-1

19=n-1

n=19+1

n=20

therefore no.of term =20