Question

Name the property used:

1) $40+(-37)=-37+40$

2.) $15-103$ is an integer.

3.) $-21+70$ is an integer.

4.) $(-15+7)+(-18)=-15+(7+(-18\left)\right)$

Answer 1

1.) $40+(-37)=-37+40$

commutative property, $a+b=b+a$

2.) $15-103$ is an integer $=$ closure property

3.) $-21+70$ is an integer $=$ sum and difference of two integers is always an integer.

4.) $(-15+7)+(-18)=-15+(7+(-18\left)\right)$

Associative property $(a+b)+c=a+(b+c)$