Find the value of ( + + ) if
²+b²+c²= 14 and + + = 6
Answers
Follow the steps:-
Step-by-step explanation:
Lol, I also don't know... sry
Answer:
I hope it helps you
please mark me as brainy please mark me
Step-by-step explanation:
In an earlier answer (May 6, 2018) to a question by the same author, I derived the following two relations:
a³+b³+c³ -3abc = (a+b+c)³ -3(ab+bc+ca) (a+b+c)………………………………..…...(1)
(a+b+c)² = a² + b² + c² + 2 (ab+bc+ca)…………………………………………………….(2)
Using the above two equations (1) and (2), we can find the answer to abc. We are given,
a+b+c=6, a²+b²+c²=14 and a³+b³+c³=36……………………………..…………………(A)
From eq.(2),
2 (ab+bc+ca) = (a+b+c)² - (a² + b² + c²)
= 6² - 14 = 36–14=22 [Using eq.(A)]
Or, ab+bc+ca = 11………………………………………………………………………………(B)
We now substitute the numerical values given in equations (A) and (B) into eq.(1) and obtain,
36 - 3abc = 6³ - 3 x 11 x 6 = 216 - 198 = 18
Or, -3abc = 18–36=-18 This yields
abc = -18/-3 = 6 (Proved)