Question

a+b+c= 9 and ab+bc+ca=26, then the value of a ^3+ b ^3 + c^3- 3abc is

Answer 1

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here ur answerGiven, a + b + c = 9 and ab + bc + ca = 26
Now, a3 + b3 + c3 - 3abc = (a + b + c) (a2 + b2 + c2 - ab - bc - ca)
Again, (a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca
⇒ a2 + b2 + c2 = (a + b + c)2 - 2 (ab + bc + ca)
⇒ a2 + b2 + c2 = (9)2 - 2 (26) = 81- 52= 29
⇒a3 + b3 + c3 - 3abc = (a + b + c) [a2 + b2 + c2 - (ab + bc + ca)]
⇒a3 + b3 + c3 - 3abc = (9) [29- (26)]
⇒a3 + b3 + c3 - 3abc = (9) [29 - (26)] = 3(3) = 9Hope it helps!If you like my answer then plzmark it brainliest...