Question

Find the sum of m terms of an A. P. whose nth terms is given by an= 5 − 6n.
pls answer i will mark as branliest

Answer 1

Step-by-step explanation:

hope u will understand

Answer 2

a1 = 5-6n

= 5-6(1)

= - 1

a2 = 5- 6 ( 2 )

= - 7

d = -7 + 1

= -6

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

Sm = m / 2 [ -2 + ( m - 1 ) -6 ]

Sm = m / 2 ( - 2 - 6 m + 6 )

Sm = m / 2 ( -6m +4 )

Sm = m / 2 ( -3m + 2 ) 2

sm = -3 m square + 2 m