Question 291203
Simplify and rationalize the denominator where necessary.
a) {{{ sqrt( 90 ) /   sqrt( 3 ) }}}
= {{{sqrt(90/3)}}}
= {{{sqrt(30)}}}
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b) {{{ 15/  (3 + sqrt( 5 )) }}}
Multiply NUM and DEN by the conjugate of the DEN 3 - sqrt(5)
= {{{15(3-sqrt(5))/(9 - 5)}}}
= {{{15(3-sqrt(5))/4}}}