If a+b+c =8 , a²+b+c²=26,

Then Find, ab+bc+ca

Asked by justjasonpong | 28th Dec, 2018, 06:17: PM

Expert Answer:

a + b + c = 8 , a² + b2 + c² = 26
 
Using
(a + b + c)2 = a² + b2 + c² + 2(ab + bc + ca)
82 = 26 + 2(ab + bc + ca)
64 - 26 = 2(ab + bc + ca)
2(ab + bc + ca) = 38
ab + bc + ca = 19

Answered by Sneha shidid | 31st Dec, 2018, 09:40: AM