Question

if a+b+c=5,a^+b^+c^=29, then find the value of ab +bc+ca​

Answer 1

Answer:

Step-by-step explanation:

Step-by-step explanation:

Given that,

a+b-c = 5 and a^2+b^2+c^2 = 29

Using the formula

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

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

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

=>5^2= 29+2(ab-bc-ca)

=>25= 29+2(ab-bc-ca)

=>ab-bc-ca= 25-29/2

=>ab-bc-ca= -4/2

=>ab-bc-ca= -2

Ans: -2