Question

please give me answer......​

Answer 1

Solution

Given :-

• x + 1/x = 3 -------(1)

Find :-

• Value of ( x³ + 1/x³ + 1)

Explanation

Using Formula

★ ( a + b)² = ( a² + b² + 2ab)

★ ( a + b)³ = ( a³ + b³ + 3a²b + 3ab²)

So, Squaring both side of equ(1)

==> (x + 1/x)² = 3²

==> x² + 1/x² + 2 * x * 1/x = 9

==> x² + 1/x² + 2 = 9

==> x² + 1/x² = 9 - 2

==> x² + 1/x² = 7----------(2)

Again, cube of equ(1) both sides

==> (x + 1/x)³ = 3³

==> x³ + 1/x³ + 3 * x² * 1/x + 3 * x * 1/x² = 27

==> x³ + 1/x³ + 3 ( x + 1/x) = 27

Keep value by equ(1)

==> x³ + 1/x³ + 3(3) = 27

==> x³ + 1/x³ = 27 - 9

==> x³ + 1/x³ = 18

Add by 1 on both side

==> x³ + 1/x³ + 1 = 18 + 1

==> x³ + 1/x³ + 1 = 19 [ Ans]

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Answer 2

Answer:

19 is answer of question