Question

rationalise the denominator of unroot 5/ 2-root7​

Answer 1

$\frac{5}{2 - \sqrt{7} }$

$\frac{5}{2 - \sqrt{7} } \times \frac{2 + \sqrt{7} }{2 + \sqrt{7} }$

$\frac{10 + 35}{(2) {}^{2} - ( \sqrt{7} ) {}^{2} }$

$\frac{45}{4 - 7}$

$\frac{45}{ - 3}$

$= - 15$

Answer 2

Answer:

5/(2-√7)

=5/(2-√7) x (2+√7)/(2+√7)

=5(2+√7)/4-7

=(10+5√7)/-3

=(-10-5√7)/3