6. If you are being asked to add a negative number by a postive number the largest numbers sign will carry over to the answer. Ex.) -15+9=-6
15 + 9 = 24
They sum up to 15
15 +26+9+12
-3
9 + -15 + 8 = 2
9
The commutative property.
9 plus 11 (20) plus 15 (35) plus 18 is equal to 53
25+15=40+9=49
It is: 2/15 plus 3/9 = 7/15
9*4 + 9*15 = 9*19 = 171.
10+9+15+8+4+6+11=63
5+9+1 = 15