Question

If a + b = 10 and a² + b² = 58, find the value of a³ + b³

Answer 1

Explanation:

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Answer 2

a³ + b³ = 370

Explanation:

Given: a + b = 10

a² + b² = 58

Find: a³ + b³

We know that (a+b)² = a² + b² + 2ab

(10)² = 58 + 2ab

100 = 58 + 2ab

100 - 58 = 2ab

42 = 2ab

21= ab

(a+b)³ = a³ + b³ + 3ab (a+b)

10³ = a³ + b³ + (3 * 21 * 10)

a³ + b³ = 1000 - 630  

a³ + b³ = 370