How do you rationalize the denominator and simplify 5/(sqrt3-1)?

1 Answer
Apr 15, 2016

=(5sqrt 3 + 5 ) / 2

Explanation:

5 / (sqrt3 -1 )

To rationalize the expression, we multiply it by the conjugate of the denominator color(blue)((sqrt 3 + 1 ))

(5 * color(blue)((sqrt 3 + 1 ) ))/ ((sqrt3 -1 ) * color(blue)((sqrt 3 + 1 ))

=((5 * color(blue)((sqrt 3)) + 5 * color(blue)(( 1 )) ))/ ((sqrt3 -1 ) * color(blue)((sqrt 3 + 1 ))

=(5sqrt 3 + 5 ) / ((sqrt3 -1 ) * color(blue)((sqrt 3 + 1 ))

  • Applying property
    color(blue)((a-b)(a+b) = a ^2 - b^2 to the denominator we get:

=(5sqrt 3 + 5 ) / ((sqrt3) ^2 -1^2)

=(5sqrt 3 + 5 ) / (3 -1 )

=(5sqrt 3 + 5 ) / 2