若a,b为实数,且b=根号3-5a+根号5a-3+15,试求根号a分之b+b分之a+2-根号a分之b+b分之a-2的值

∵b=根号3-5a+根号5a-3+15
∴3-5a≥0 5a-3≥0
∴a=3/5
b=15
∴根号a分之b+b分之a+2-根号a分之b+b分之a-2
=√(b²+a²+2ab)/ab-√(b²+a²-2ab)/ab
=√(a+b)²/ab-√(b-a)²/ab
=(a+b）/ab*√ab-(b-a)/ab*√ab
=√(ab)/ab*(a+b-b+a)
=2√（ab）/b
=2√(15*3/5)/15
=2/5