First one I think I really don’t know
Answer:
-15 + 7 = -8
You have to add -15 plus positive 7 to get -8.
Hope this helps.
Answer:

Center of mass at 
Step-by-step explanation:
Given a set of objects
located at the points
The moments Mx and My are calculated as follows.

and the Center of mass is given at the coordinates
where M is the total mass of the system.
We have that m1=3, m2=4 and m3=3, so M = 3+4+3 = 10.
We have that m1 is at point P1(2,-6), m2 at point P2(-3,2) and m3 at point P3 (3,4), then


Then, the center of Mass is at 
Answer:
2(x + y)
Step-by-step explanation:
You can pull out a 2 from the expression.
So divide 2x by 2 and 2y by 2.
2x/2 = x
2y/2 = y
2(x + y)