Find the value of a3 + b3 +c3
– 3abc, when a + b + c = 8 and a b + b c +c a = 25
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and step by step plzzzzz
Answers
Answered by
7
Answer:
-88
Step-by-step explanation:
Given, a + b + c = 8
On Squaring both sides, we get
=> (a + b + c)² = (8)²
=> a² + b² + c² + 2ab + 2bc + 2ca = 64
=> a² + b² + c² + 2(ab + bc + ca) = 64
=> a² + b² + c² + 2(25) = 64
=> a² + b² + c² + 50 = 64
=> a² + b² + c² = 64 - 50
=> a² + b² + c² = 14
Now,
We know that,
a³ + b³ + c³ - 3abc = (a + b + c) (a² + b² + c² - ab - bc - ca)
=> a³ + b³ + c³ - 3abc = (a + b + c) [a² + b² + c² -(ab + bc + ca)]
=> a³ + b³ + c³ - 3abc = (8) [14 - 25]
=> a³ + b³ + c³ - 3abc = 8 (-11)
a³ + b³ + c³ - 3abc = - 88
Hope it helps!
Answered by
1
Answer:
thank you for your answer
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