Question

сократите дробь b^2-13/√13+b и вторую​

Answer 1

$\dfrac{b^2-13}{\sqrt{13}+b} = \dfrac{(b-\sqrt{13})(b+\sqrt{13})}{\sqrt{13}+b} = b-\sqrt{13}$

$\dfrac{a^2-2\sqrt5+5}{a-\sqrt5} = \dfrac{a^2-2\sqrt5+5}{a-\sqrt5}*\dfrac{a+\sqrt5}{a+\sqrt5} = \dfrac{(a^2-2\sqrt5+5)(a+\sqrt5)}{(a-\sqrt5)(a+\sqrt5)}= \\\\\\=\dfrac{a^3+\sqrt5a^2-2\sqrt5a-10+5a+5\sqrt5}{a^2-5}$