How do you simplify #5/(8+sqrt(7))#?

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Answer 1 · 2015-10-22T18:10:14

#(40-5sqrt7)/57#

Original expression

#5/(8+sqrt7)#

Multiply by conjugate

#5/(8+sqrt7)*(8-sqrt7)/(8-sqrt7)#

combine

#(5*(8 - sqrt7))/((8*8)-sqrt7*sqrt7)#

Collect terms

#(40-5sqrt7)/(64-7)# #rArr# #(40-5sqrt7)/(57)#

#~~0.47#