Question 188343
{{{7*sqrt(90)}}} Start with the given expression.



{{{7*sqrt(9*10)}}} Factor {{{90}}} into {{{9*10}}}



{{{7*sqrt(9)*sqrt(10)}}} Break up the square root.



{{{7*3*sqrt(10)}}} Take the square root of 9 to get 3



{{{21*sqrt(10)}}} Multiply



So {{{7*sqrt(90)=21*sqrt(10)}}}