32÷(6-2sqrt5)32÷(6−2√5)
means
32/(6-2sqrt5)326−2√5
multiply by the conjugate
32/(6-2sqrt5)*(6+2sqrt5)/(6+2sqrt5)326−2√5⋅6+2√56+2√5
color(red)((6-2sqrt5)*(6+2sqrt5) = 6^2 - (2sqrt5)^2=36-20 = 16)(6−2√5)⋅(6+2√5)=62−(2√5)2=36−20=16
color(red)("difference of two sequares")difference of two sequares
(32*(6+2sqrt5))/ 1632⋅(6+2√5)16
color(red)(32/16 = 2)3216=2
2*(6+2sqrt5) = 12+4sqrt52⋅(6+2√5)=12+4√5