Answer:
A , and C
Step-by-step explanation:
A. 2.3+(-2.3) ➡ 2.3 -2.3 = 0 so this option is correct
B.-3.7+(-4.1) ➡ -3.7 - 4.1 = -7.8 so this option isn't correct
C.-2.6-(-12/4) ➡-2.6 + 3 = 0.4 this option is also correct
D. (5/2)+(-2.5) ➡ 5/2 -5/2 = 0 this one would be undefined because we can't divide 0 by 2 or any other rational numbers
E.72-(-100) ➡72+100= 172 is positive not negative therefore this option is incorrect