Answer:
A. 4+(-4),
D. -9+9
Step-by-step explanation:
A expression has a sum of 0 when we have two equal numbers with inverse signals.
A. 4+(-4)
We have the same number(4), and they have inverse signals. So this expression has a sum of 0.
B. 6.3 +(-3.6)
6.3 and 3.6 are different numbers, so this expression does not have a sum of 0.
C. 13+(-11)
13 and 11 are different numbers, so this expression does not have a sum of 0.
D. -9+9
We have the same number(9), with inverse signals. So yes, this expression has a sum of 0.
