Question 143490
Given : {{{7*sqrt(45) - 2*sqrt(5)}}}
{{{7*sqrt(9*5) - 2*sqrt(5)}}}
{{{7*sqrt(9)*sqrt(5) - 2*sqrt(5)}}}
{{{7*3*sqrt(5) - 2*sqrt(5)}}}
{{{21*sqrt(5) - 2*sqrt(5)}}}
{{{sqrt(5)* (21 -2)}}}
{{{19*sqrt(5)}}}