The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Find the sum? Choose one.
A) 30
B) 15
C) 40
D) 45
E) 20
a2+b2+c2=138 and(ab+bc+ca)=131   a+b+c^2=400   root(400)=20   ANSW20R 20
<result>E</result>
The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Find the sum?