√a-√(a-6)=2 √a -2 =√(a-6)a+4-4√a =a-62√a =5√a =5/2a=25/4√a+√(a+6) = 5/2 + √(24/4+6) = 5/2+7/2 = 6根号（5+2√6）+ 根号（7-2√10）= 根号(√3+√2)^2 + 根号(√5-√2)^2= √3+√2 + √5-√2= √3+√...