x^2-(2+√2)x+√2-3=0
△=(2+√2)^2-4(√2-3）
=6+4√2-4√2+12
=18
√△=3√2
x1=（2+√2+3√2）÷2=1+2√2
x2=（2+√2-3√2）÷2=1-√2