Question 491135
{{{14/(3-sqrt (7))}}}

Multiply numerator & denominator by the conjugate (3+sqrt(7))

{{{14(3+sqrt(7))/((3-sqrt(7))(3+sqrt(7)))}}}

Apply formula (a+b)(a-b) = a^2-b^2 for the denominator

{{{14(3+sqrt(7))/(9-7)}}}

{{{(7*(cross(2))(3+sqrt(7)))/(cross(2))}}}

{{{7*(3+sqrt(7))}}}

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