Question

pls answer my questions​

Answer 1

Answer:

Hope it helps you!!!! !!

Answer 2

Given :

• x²+y² = 25

• xy = 12

To find :

${x}^{ - 1} + {y}^{ - 1}$

Solution :

$\implies {x}^{ - 1} + {y}^{ - 1} = \dfrac{1}{x} + \dfrac{1}{y}$

$\implies \dfrac{1}{x} + \dfrac{1}{y} = \dfrac{x + y}{xy}$

value of xy is given as 12.

We have to find out the value of x+y.

$\implies \: {(x + y)}^{2} = {x}^{2} + {y}^{2} + 2xy$

put :-

• x²+y²= 25

• xy = 12

$\implies \: {(x + y)}^{2} = 25 +( 2 \times 12)$

$\implies \: {(x + y)}^{2} = 25 +24$

$\implies \: {(x + y)}^{2} = 49$

$\implies \: {(x + y)} = \sqrt{49}$

$\implies \: {(x + y)} = \pm 7$

therefore now :-

$\implies \dfrac{x + y}{xy} = \dfrac{\pm7}{12}$

Answer :

$\implies {x}^{ - 1} + {y}^{ - 1} = \dfrac{\pm7}{12}$

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$\implies{(a+b)^2 = a^2 + b^2 + 2ab}$

$\implies{(a-b)^2 = a^2 + b^2 - 2ab}$

$\implies{(a+b)^3 = a^3 + b^3 + 3ab(a + b)}$

$\implies{(a-b)^3 = a^3 - b^3 - 3ab(a-b)}$

$\implies{(a^3+b^3)= (a+b)(a^2 - ab + b^2)}$

$\implies{(a^3-b^3)= (a-b)(a^2 + ab + b^2)}$

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