a+b+c=9and a square +b square +c square =29 find ab+bc+ca
Answers
Answered by
1
Answer:
ab + bc + ca = 26
Step-by-step explanation:
Given,
a + b + c = 9
a^2 + b^2 + c^2 = 29
To find : ab + bc + ca = ?
( a + b + c )^2 = 9^2
( a + b + c )^2 = a^2 + b^2 + c^2 + 2 ( ab + bc + ca ) { formula / identity }
9^2 = 29 + 2 ( ab + bc + ca )
81 = 29 + 2 ( ab + bc + ca )
81 - 29 = 2 ( ab + bc + ca )
52 = 2 ( ab + bc + ca )
ab + bc + ca = 52 / 2
ab + bc + ca = 26
Similar questions