How do you add #(4+sqrt50) - (3-sqrt8)#?

1 Answer
Alan P.
Apr 14, 2015

Extract the squares from within the roots:
#(color(red)(4)+color(blue)(sqrt(50)))-(color(red)(3)-color(blue)(sqrt(8)))#

#=(color(red)(4)+color(blue)(5sqrt(2)))-(color(red)(3)-color(blue)(2sqrt(2)))#

#= color(red)(4-3) +color(blue)(5sqrt(2)+2sqrt(2))#
(don't forget to switch the sign on #2sqrt(2)#!)

#= 1+7sqrt(2)#

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