Question

Racionalize os denominadores.

a) 7.√5
____
√5

b) 3
___
√8

Answer 1

$a) \frac{7\sqrt{5}}{\sqrt{5}} \times \frac{\sqrt{5}}{\sqrt{5}} = \frac{7\sqrt{5^2}}{\sqrt{5^2}} = \frac{7 \times 5}{5} = 7 \\ \\ b) \frac{3}{\sqrt{8}} \times \frac{\sqrt{8}}{\sqrt{8}} = \frac{3\sqrt{8}}{\sqrt{8^2}} = \frac{3\sqrt{8}}{8} = \frac{3\sqrt{2^2 \times 2}}{8} = \frac{3 \times 2 \sqrt{2}}{8} = \frac{3\sqrt{2}}{4}$

Answer 2

a) 7.✓5
-----------
√5

7.√5 √5
--------* -------
√5 √5

7.5
----- = 7
5

b) 3
---------
√8

3 √8
---- * ----
√8 √8

3√8
------
8