Math, asked by SLAYER1, 1 year ago

plzzz solve : (7+root 5)/(7 - root 5 ) - (7 - root 5) / (7 + root 5 ) = a + 7 / 11 × root 5 × b : find a and b.

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Answers

Answered by varunrockgta
46

This is the right answer please mark the brilliant



Step-by-step explanation:


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Answered by Haezel
5

Answer:

The value of a and b are 0 and 2/11 respectively.

Step-by-step explanation:

For first case we use  

Now to rationalize the above value we multiply both the numerator and denominator by \bold{7+\sqrt{5}}

\begin{array}{l}{\left[\frac{7+\sqrt{5}}{7-\sqrt{5}}\right]\left[\frac{7+\sqrt{5}}{7+\sqrt{5}}\right]} \\ {=\frac{7^{2}+\sqrt{5}^{2}+2 \sqrt{5} .7}{49-5}} \\ {=\frac{49+5+14 \sqrt{5}}{44}} \\ {=\frac{54+14 \sqrt{5}}{44}}\end{array}

For second case we can use

Now to rationalize the above value we multiply \bold{7-\sqrt{5}}in numerator and denominator.

\begin{array}{l}{\left[\frac{7-\sqrt{5}}{7+\sqrt{5}}\right]\left[\frac{7-\sqrt{5}}{7-\sqrt{5}}\right]} \\ {=\frac{7^{2}+\sqrt{5}^{2}-2 \sqrt{5} .7}{49-5}} \\ {=\frac{49+5-14 \sqrt{5}}{44}} \\ {=\frac{54-14 \sqrt{5}}{44}}\end{array}

Adding both the cases we get  \frac{54+14 \sqrt{5}}{44}+\frac{54-14 \sqrt{5}}{44}=\frac{14 \sqrt{5}}{11}

Therefore equating \frac{14 \sqrt{5}}{11}=a+7 \sqrt{5 b}0+\frac{14 \sqrt{5}}{11}=a+7 \sqrt{5 b}

We get a = 0 and b =  2/11  

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