Question

a2+ b2 + c2 =251 , 1/2(ab+ bc+ ca) =3, then find a+ b+ c​

Answer 1

Answer:

$\sqrt{ \frac{754}{3} }$

Step-by-step explanation:

(a+b+c)²=a²+b²+c²+2(ab+bc+ca)

• 1/2(ab+bc+ca)=3
• 3[2(ab+ba+ca)]=1
• 2(ab+bc+ca)=1/3

(a+b+c)²=251+1/3

(a+b+c)²=754/3

a+b+c=

$\sqrt{ \frac{754}{3} }$

.