Question

find the sum of 12 terms of A.P -37, -33, -29...........​

Answer 1

Answer:

-180

Step-by-step explanation:

a = -37

d = -33 -(-37) = -33 + 37 = 4

formula for sum to n terms, sn = (n/2) (2a+ (n-1) d)

sum to 12 terms

s12 = (12/2) (2x-37 + ( 12-1)x4) = 6(-74 + 11x4) = 6(-74+44) = 6x-30 = -180

Answer 2

d= t2 - t1 = -33+37 = 4

TN= a+(n-1) d

t12= -37 + (12-1) 4

= -37+11*4

= -37+44

= 7