Question

find the value of a and b please help me​

Answer 1

Step-by-step explanation:

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Answer 2

Answer:

a = 0

b = - 2/3

Step-by-step explanation:

Given:

$\dfrac{ \sqrt{7} - 1}{ \sqrt{7} + 1 } - \dfrac{ \sqrt{7} + 1}{ \sqrt{7} - 1} = a + b \sqrt{7}$

To find:

Value of a and b .

Solution:

This a like fraction We don't need to rationalize it just simplify.

Note : When the denominator of fractions are same but differ from sign they called as like fraction .

L.H.S

$\dfrac{ \sqrt{7} - 1}{ \sqrt{7} + 1 } - \dfrac{ \sqrt{7} + 1}{ \sqrt{7} - 1} \\ \\ \frac{( \sqrt{7} - 1) {}^{2} - {( \sqrt{7} + 1) }^{2} }{( \sqrt{7} + 1)( \sqrt{7} - 1) } \\ \\ \frac{ - 4 \times \sqrt{7} \times 1}{ ({ \sqrt{7}) }^{2} - {1}^{2} } \\ \\ \frac{ - 4 \sqrt{7} }{7 - 1} \\ \\ \frac{ - 4 \sqrt{7} }{6} \\ \\ \frac{ - 2 \sqrt{7} }{3} \\ \\ 0 - \frac{2 \sqrt{7} }{3}$

Comparing the L.H.S from R.H.S, I get ...

a = 0

b√7 = - 2√7/3

b = - 2/3