The masses mi are located at points pi. Find the moments mx and my and the center of mass of the system. M1=2
M2=9
M3=10

P1 (1,5)
P2 (3,-2)
P3 (-2,-1)

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.