Question

I need the answer ASAP

Answer 1

In order to rationalize the denominator of the fraction, we need to multiply the fraction by the conjugate of the expression in the denominator.

The conjugate is the same expression but with the signal between the numbers changed.

So we have:

`\frac{4}{3+\sqrt[]{7}}=\frac{4}{3+\sqrt[]{7}}\cdot\frac{3-\sqrt[]{7}}{3-\sqrt[]{7}}=\frac{4(3-\sqrt[]{7})}{3^2-(\sqrt[]{7})^2}=\frac{12-4\sqrt[]{7}}{9-7}=\frac{12-4\sqrt[]{7}}{2}`

So the new denominator of the fraction is 2, therefore the correct option is D.