A, it's always true
remember commutative property
a+b=b+a
a and b can be negativ numbers
so equatinos
-5.2+7.71=2.51
7.71-5.2=2.51
-8.65+3.94=-4.62
3.94-8.65=-4.62
B.
-5.2-7.71=-12.91
7.71-(-5.2)=12.91
-8.65-3.94=-12.59
3.94-(-8.65)=12.59
always false
C. when you change the order, you are subtracting a different number from a different number than before