Order from least to greatest
sqrt(21) - sqrt(27), -sqrt(16) + sqrt(25), sqrt(27) + sqrt(25), sqrt(27) - sqrt(21)
sqrt(21) - sqrt(27) = the smallest
-sqrt(16) + sqrt(25) = -4 + 5 = 1
sqrt(27) + sqrt(25) = the greatest
sqrt(27) - sqrt(21) = .613
I'll let you take it from here
