x-y=(√2)²
2x+5y- 3/8=(-3/2)³
整理,得
x-y=2 (1)
2x+5y=-3 (2)
(1)×5+(2)
7x=7
x=1
代入(1)
y=x-2=1-2=-1
√(x²-y²)=√[1²-(-1)²]=√(1-1)=0