已知x²-xy=8 xy-y²=3 则x²-y²的值为( ),x²-2xy+y²的值为( ).
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![已知x²-xy=8 xy-y²=3 则x²-y²的值为( ),x²-2xy+y²的值为( ).](/uploads/image/z/1644759-63-9.jpg?t=%E5%B7%B2%E7%9F%A5x%26%23178%3B-xy%3D8+xy-y%26%23178%3B%3D3+%E5%88%99x%26%23178%3B-y%26%23178%3B%E7%9A%84%E5%80%BC%E4%B8%BA%EF%BC%88+%EF%BC%89%2Cx%26%23178%3B-2xy%2By%26%23178%3B%E7%9A%84%E5%80%BC%E4%B8%BA%EF%BC%88+%EF%BC%89.)
已知x²-xy=8 xy-y²=3 则x²-y²的值为( ),x²-2xy+y²的值为( ).
已知x²-xy=8 xy-y²=3 则x²-y²的值为( ),x²-2xy+y²的值为( ).
已知x²-xy=8 xy-y²=3 则x²-y²的值为( ),x²-2xy+y²的值为( ).
已知x²-xy=8 xy-y²=3 则x²-y²的值为(11 ),x²-2xy+y²的值为(5 ).
x²-y²=(x²-xy)+(xy-y²)=8+3=11
x²-2xy+y²=(x²-xy)-(xy-y²)=8-3=5
1式加2式 11,1式-2式 5