If #(36+16(5)^(1/2))^(1/2)= a+b(c)^(1/2)# where #a#, #b#, and #c# are positive integers, find #a*b*c#?

1 Answer
Apr 6, 2018

#(36+16(5)^(1/2))^(1/2)= a+b(c)^(1/2)#

#=>(16+20+16(5)^(1/2))^(1/2)= a+b(c)^(1/2)#

#=>(4^2+(2*5^(1/2))^2+2*4*2(5)^(1/2))^(1/2)= a+b(c)^(1/2)#

#=>[(4+2*5^(1/2))^2]^(1/2)= a+b(c)^(1/2)#

#=>4+2*5^(1/2)= a+b(c)^(1/2)#

Comparing both sides we get

#a=4,b=2and c=5#