$\frac{1}{ \sqrt{7} -(- 2)} \\ rationalizing \: \: \: the \: \: \: denominator \: \: \: we \: \: \: have \\ = \frac{1}{ \sqrt{7} + 2 } \times \frac{ \sqrt{7} - 2}{ \sqrt{7} - 2} \\ = \frac{ \sqrt{7} - 2}{ {( \sqrt{7} )}^{2} - {(2)}^{2} } \\ = \frac{ \sqrt{7} - 2 }{7 - 4} \\ = \frac{ \sqrt{7} - 2}{3}$

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Doubt clarification - use comment section.

3 0

2 years ago

Read 2 more answers

Six yellow marbles and four blue marbles arecollected. All ten

Alex73 [517]

4 of a 10 because there is 4 blue marbles and 6 yellow

6 0

3 years ago

How can you use doubles when multiplying with 4 to find 4x8

pshichka [43]

4 = 2 * 2

Multiplying by 2 is the same a doubling.
Since 4 is 2 * 2, to multiply a number by 4, double the number twice.

Example:
What is 4 * 100?
Double 100 to get 200.
Double 200 to get 400.
Therefore, 4 * 100 = 400.
By doubling twice, we do the same as multiplying by 4.

4 0

3 years ago