Question

Rationalise the denominator of 3 7+2√5 .

Answer 1

Pls mark as brainliest answer

Answer 2

$\sf{\underline{\underline{\boxed{\huge{\red{\mathsf{ Solution }}}}}}}$

$\sf\longrightarrow \dfrac{3}{7 + 2\sqrt{5}}$

• multiply and divide the numerator with the -( denominator )

$\sf\longrightarrow \dfrac{3}{7 + 2\sqrt{5}}\times \dfrac{7 - 2\sqrt{5}}{7-2\sqrt{5}}$

• $\sf\boxed{ ( a + b) ( a - b ) = a^2 - b^2 }$

$\sf\longrightarrow \dfrac{21 +6\sqrt{5}}{49 - 20}$

$\sf\longrightarrow \dfrac{21 + 6\sqrt 5}{29}$