Answer:
D
Explanation:
In the original expression = 37.4 - 54.9 = -17.5 
So, we have to solve all the equations but 1 of them has to equal to -17.5
A) -54.9 + (-37.4) = -92.3
 Remove parentheses
 = -54.9 - 37.4
Subtract the numbers
 -92.3
B) 54.9 - 37.4 = 17.5
 Since 54.9 is greater than 37.4 just subtract normally
 4 14
 5 4. 9 < ------- Line up the decimal points like this
- 3 7. 4 <--------- Subtract the decimals
-----------------
 1 7 . 5 <---------- This is the final answer to B. 
 
C) 37.4 - (- 54.9) = 92.3
 Change the sign to addition
 =37.4 + 54.9
 Add the numbers normally
 54.9
+ 37. 4
--------------
 92.3
D) 37.4 + (-54.9) = -17.5
 Change the sign to subtraction
 = 37.4 - 54.9
Subtract them normally (but as you can see you are subtracting a smaller number from a larger number so heres a trick that you can use switch the equation by putting the larger number in first like this....)
54.9 - 37.4 = 17.5 (REMEMBER the answer is not 17.5 because the original equation of D is reversed 37.4 - 54.9 so in this case your answer should be
 - 17.5)
37.4 - 54.9 = -17.5
Your final answer is D because it matches 37.4 - 54.9.
Hope this helps!