Question

If a+b+c=9 and a2+b2+c2=35 find the value of ab+bc+ca

Answer 1

Step-by-step explanation:

Using identity

(a+b+c) =a^2 +b^2 + c^2 +2(ab +bc +ca)

(9)^2. =. 35. +2(ab +bc +ca)

81. =. 35. +2(ab+bc+ ca)

81-35. =. 2(ab+bc+ca)

46=2(ab+bc+ca)

ab+bc+ca. =46/2

ab + bc +ca =23

Please Follow me and mark as brainlist

Answer 2

Answer:ab+bc+ca=23

Step-by-step explanation

(a+b+c)²=a²+b²+c²+2(ab+bc+ca)

81=35+2(ab+bc+ca)

2(ab+bc+ca)=46

ab+bc+ca=23