（根号2-1）乘以（根号3-1）-1除以（根号2-1）+2除以（根号3-1）
=（√2-1)(√3-1)-1/(√2+1)+2/(√3-1)
=（√2-1)(√3-1)-（√2-1)/[(√2+1)（√2-1)]+2(√3+1)/[(√3-1)(√3+1)]
=(√2-1)(√3-1)-（√2-1)+(√3+1)
=(√2-1)(√3-1-1)+(√3+1)
=(√2-1)(√3-2)+(√3+1)
=√6-2√2-√3+2+√3+1
=√6-2√2+3