Question

iii) If a = -9, d=-7 then t19=?
(A) 117
(B) 135
(C)-117
(D) -135 this is a sum of arithematic progression​

Answer 1

Answer:

option D

An = a+(n-1)d ------> -9+-126 = -135

Answer 2

option D

Step-by-step explanation:

n=a+(n-1)d.......

t19=-9+(19-1)-7

=-9+18(-7)

=-9-126

=-135.......

Kamrul Hasan