Question

The 5th term openepi is -3 and its common difference is -4 and the sum of its first ten terms is

Answer 1

Answer:

sun of its first ten terms is -50

Step-by-step explanation:

a5 = -3

d = -4

find a

a5 = a + (n-1) × d

-3 = a + (5 - 1) ×(-4)

-3 = a + 4 × (-4)

-3 = a - 16

-3 + 16 = a

a = 13

sum of first 10 terms

S10 = n/2(2a + [n - 1]d)

= 10/2(2×13 + [10 - 1]{-4})

= 5(26 + 9{-4})

= 5(26 - 36)

= 5(-10)

S10 = -50