我是准高二党只会做第三题.另外两道再想想.
将两式相减知X²- X+Y-Y²=0
移项后有X²-Y²=X-Y ,即(X-Y)(X+Y)-(X-Y)=0所以(X-Y)(X+Y-1)=0
所以X-Y=0①或X+Y-1=0②
再将①代入原方程组解得X=1和Y=2
将②代入原方程组解得X=(1-√5)/2,Y=(1+√5)/2或者X=(1+√5)/2,Y=(1-√5)/2