Question

please help guys.please ​

Answer 1

25 is the only multiple of 5 in it so go for it!

Answer 2

Question -

If  $\sf{x+\frac{1}{x}=5\:}$ then $\sf{x^2+\frac{1}{x^2}\:}$ is

• 23
• 25
• 0
• 27

Solution -

Firstly we will be squaring both the sides of the given equation,

$\implies\sf{(x+\frac{1}{x})^2=(5)^2\:}$

Opening the bracket on L.H.S by applying the algebraic identity -

         (a + b)² = a² + b² + 2ab

$\implies\sf{x^2+\frac{1}{x^2}+2\times\cancel{ x}\times \frac{1}{\cancel{x}} =25\:}$

$\implies\sf{x^2+\frac{1}{x^2}=25-2\:}$

$\implies\bf{x^2+\frac{1}{x^2}=23\:}$

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