Basically there are 3 addition properties and they are associative property, identity property, and commutative property.
Commutative property is just changing the order of the addends. Example: 26+19+34+21= 21+34+19+26
Identity Property is just adding a 0 to the number that doesnt change anything. Example: 26+19+34+21 +0 = 100
Associative property is just changing the grouping of the addends. Example: (26+19) + (34+21)
I know these properties may be complicated i know inhate them too haha but i hope i helped :) if you want you can search up the distributive property too but its with multiplication and addition combined and its harder but i think these are the 3 main properties.
sorry wait please delete my answer I realized my mistake!
Answer:
(6,8)
Step-by-step explanation:
midpoint=(x1+x2)÷2,(y1+y2)÷2
a(4,15) b(8,1)
x=4+8=12÷2=6
y=15+1=16÷2=8
Answer=(6,8)
A. x(x+7)=23 us the correct answer i believe