Question 935160

I have solved many algebric questions but i faced problems in simplyfing the answar having sqrt_to match with books answer. Kindly simplyfy it my ans
49/(7-sqrt42)

The book ans is 
7(7+sqrt42)
<pre>
{{{49/(7 - sqrt(42))}}}
{{{49(7 + sqrt(42))/(7 - sqrt(42))(7 + sqrt(42))}}} ------- Rationalizing denominator
{{{49(7 + sqrt(42))/(49 - 42)}}} ------------ FOILing denominator
{{{49(7 + sqrt(42))/7}}}
{{{7cross(49)(7 + sqrt(42))/cross(7)}}}________{{{highlight_green(highlight_green(7(7 + sqrt(42))))}}}