Question

-3,-6,-9 find S15 std 10​

Answer 1

Answer:

a = -3

d = -3

s15 = 15\2 ( 2×-3 + 14×-3)

s15 = 15\2 ( -6 -42)

s 15 = 15\2 (-48)

s15 = 15 ( -24)

s 15 = -360

Answer 2

Answer:

15÷ 2( 2 ×-3 +(15-1)(-3)

15÷2 ( -6+14×(-3)

15÷2 (-6 +(-42 )

15÷2 × -48

15×(-24)= -360