Respuesta :

10 root 10 u break the 40 to 10 and 4 then pull the 4 out

The answer is 10√10.

 
[tex]5 \sqrt{40} =5 \sqrt{4*10} =5 \sqrt{4}* \sqrt{10} =5*2* \sqrt{10} =10 \sqrt{10} [/tex]