Question 49829
  
  {{{sqrt(40)+sqrt(80)+sqrt(45)-sqrt(10)}}}
  
=  {{{sqrt(4*10)+sqrt(16*5)+sqrt(9*5)-sqrt(10)}}}
  
=  {{{2sqrt(10)+4sqrt(5)+3sqrt(5)-sqrt(10)}}}
 
=  {{{4sqrt(5)+3sqrt(5)+2sqrt(10)-sqrt(10)}}}
  
=  {{{7sqrt(5)+sqrt(10)}}}