1)x-9/√x+3 = (√x-3)(√x+3)/√x+3 = √x-3
2)5+2√5/√5= √5*(√5+2)/√5=√5+2
3)a-1/a-2√a+1 = (√a-1)(√a+1)/(√a-1)² = √a+1/√a-1
