（√2+1)/(√2-1)+(√3-1)/(√3+1)
=（√2+1)(√2+1)/(√2-1)（√2+1）+(√3-1)(√3-1)/(√3+1)(√3-1)
=(√2+1)^2+(√3-1)^2
=2+2√2+1+3-2√3+1
=2√2-3√3+6