Question

rationalise 1 by 7 + 5 root 2

Answer 1

Answer:

$= > \frac{1}{7 + 5 \sqrt{2} } \\ \\ = > \frac{1}{7 + 5 \sqrt{2} } \times \frac{7 - 5 \sqrt{2} }{7 - 5 \sqrt{2} } \\ \\ = > \frac{7 - 5 \sqrt{2} }{ {(7)}^{2} - {(5 \sqrt{2} )}^{2} } \\ \\ = > \frac{7 - 5 \sqrt{2} }{49 - 50} \\ \\ = > \frac{7 - 5 \sqrt{2} }{ - 1} \\ \\ = > - (7 - 5 \sqrt{2} ) \\ \\ = > - 7 + 5 \sqrt{2}$

Identity used:

$= > (a + b)(a - b) = {a}^{2} - {b}^{2}$

Tysm for the question!

Answer 2

➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖
ⓗⓞⓟⓔ ⓘⓣ ⓗⓔⓛⓟⓢ