The series is A.P. with first term = 44 and common difference = 39-44=-5 = 34- 39
Sum of A.P. is S = n/2(2a+ (n-1)d)
Where a is first term ,d is common difference and n no. Of terms
Here a = 44 ,d= -5 and n = 23
S = 23 /2(2×44+ (23-1)(-5))
S=23/2(88-110)
S = 23/ 2(-22)
S = 23×-11
S = -253
