Table:
0
A
B
C
D
E
1
(dollars in millions)  Increase/ (Decrease)
2
Years Ended December 31,
2019
2018
2019 vs. 2018
3
Cost of services 
31772
32185
-413
(1.3)%
4
Cost of wireless equipment 
22,954
23,323
(369)
(1.6)
5
Selling, general and administrative expense
29,896
31,083
(1,187)
(3.8)
6
Depreciation and amortization expense 
16,682
17,403
(721)
(4.1)
7
Media goodwill impairment 
186
4,591
(4,405)
(95.9)
8
Consolidated Operating Expenses
101490
108585
-7095
(6.5)

Questions and formulas:
Question: What was the change in the cost of services from 2018 to 2019?
Formula: B3 - C3
Formula2: B3 - C3
Level: Calculation
Question: What was the average cost of wireless equipment for 2018 and 2019?
Formula: (B4 + C4) / 2
Formula2: (B4 + C4) / 2
Level: Calculation
Question: What was the average Selling, general and administrative expense for 2018 and 2019?
Formula: (B5 + C5) / 2
Formula2: (B5 + C5) / 2
Level: Calculation