If a2 + b2 + c2 = 941 and ab + bc + ca = 10, then a + b + c is Choose the correct choice:
A) 44
B) 56
C) 16
D) 32
E) 31
by formula ,   (a + b + c)^2= a^2 + b^2 + c^2 + 2(ab + bc + ca),   since, a^2 + b^2 + c^2 = 941 and ab + bc + ca = 10,   (a + b + c)^2 = 941 + 2(10)   = 961   =31^2   therefore: a + b + c = 31   ANSW31R:31
<result>E</result>
If a2 + b2 + c2 = 941 and ab + bc + ca = 10, then a + b + c is