Question

$\huge\tt\red{P}\tt\pink{L}\tt\blue{E}\tt\green{A}\tt\purple{S}\tt\orange{E}$ $\huge\tt\red{A}\tt\pink{N}\tt\blue{S}\tt\green{W}\tt\purple{E}\tt\orange{R}$ ■correct answer will be marked as brainlist■ ■ wrong answer will be reported ​■​

Answer 1

Solution

Given :-

• a² + 1/a² = 27_________(1)

Find :-

• a - 1/a = ?

Explanation

Using Formula

★ (x + y)² = x² + y² + 2xy

So,

==> (a - 1/a)² = a² + 1/a² - 2

keep value by equ(1)

==> (a - 1/a)² = 27 - 2

==> (a - 1/a)² = 25

Take square root both sids

==> √(a - 1/a)² = √25

==> √(a - 1a)² = √(5×5)

==> (a - 1/a) = ±5

Hence

• Your Answer will be options number (a).

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Some Important Formula

★ (x - y)² = x² + y² - 2xy

★(x - y)³ = (x³ - y³ - 3x²y + 3xy²)

★(x + y)³ = (x³ + y³ + 3x²y + 3xy²)

★(x + y + z)² = ( x² + y² + z² + 2xy + 2yz + 2za)

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