Sum of the squares of three numbers is 579 and the sum of their products taken two at a time is 131. Find the sum? Choices
A) 20  B) 22  C) 25  D) 29  E) 28
(a + b + c)2 = a2 + b2 + c2 + 2(ab +bc + ca) = 579 + 2* 131   a + b + c = √841 = 29   29
<result>D</result>
Sum of the squares of three numbers is 579 and the sum of their products taken two at a time is 131. Find the sum?