How would the fraction [tex]\frac{7}{1-\sqrt{5} }[/tex] be rewritten if its denominator is rationalized using difference of squares?

Sagot :

Answer:

[tex] \frac{7 + 7 \sqrt{5} }{ - 4} [/tex]

Step-by-step explanation:

We would multiply the fraction by its conjugate

( A conjugate is a expression that has the same integer or number values but have different signs) for example

[tex]5x + 2[/tex]

and

[tex]5x - 2[/tex]

ARE Conjugates.

The conjugate of

[tex]1 - \sqrt{5} [/tex]

is

[tex]1 + \sqrt{5} [/tex]

So this means we will multiply the expression by 1 plus sqr root of 5 on the numerator and denominator.

Our new numerator will be

[tex]7 \times (1 + \sqrt{5} ) = 7 + 7 \sqrt{5} [/tex]

We can apply the difference of squares for the denominator.

[tex](x + y)(x - y) = x {}^{2} - {y}^{2} [/tex]

So our denominator will be

[tex]1 - 5 = - 4[/tex]

So our rationalized fraction will be

[tex] \frac{7 + 7 \sqrt{5} }{ - 4} [/tex]