【SZ080410】 已知 2x^2-3xy-2y^2=0 求(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
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【SZ080410】 已知 2x^2-3xy-2y^2=0 求(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
已知 2x^2-3xy-2y^2=0 求(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
已知 2x^2-3xy-2y^2=0 求(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
2x^2-3xy-2y^2=0
(x-2y)(2x+y)=0
x-2y=0或2x+y=0
x=2y或y=-2x
当x=2y时
(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
=(4×4y²-5×2y²+y²)/(3×4y²+3×2y²+y²)
=7y²/19y²
=7/19
当y=-2x时
原式=(4x²+10x²+4x²)/(3x²-6x²+4x²)
=18x²/x²
=18
(x-2y)(2x+y)=0
x-2y=0或2x+y=0
x=2y或y=-2x
当x=2y时
(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
=(4×4y²-5×2y²+y²)/(3×4y²+3×2y²+y²)
=7y²/19y²
=7/19
当y=-2x时
原式=(4x²+10x²+4x²)/(3x²-6x²+4x²)
=18x²/x²
=18
【SZ080410】 已知 2x^2-3xy-2y^2=0 求(4x^2-5xy+y^2)/(3x^2+3xy+y^2)
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