求助:x²+y²/ x²+2xy+y²+2/xy÷(1/x+1/y)²化简

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求助:x²+y²/x²+2xy+y²+2/xy÷(1/x+1/y)²化简求助:x²+y²/x²+2xy+y²+

求助:x²+y²/ x²+2xy+y²+2/xy÷(1/x+1/y)²化简
求助:x²+y²/ x²+2xy+y²+2/xy÷(1/x+1/y)²化简

求助:x²+y²/ x²+2xy+y²+2/xy÷(1/x+1/y)²化简
=(x²+y²)/(x+y)²+(2/xy)÷[(x+y)²/x²y²]
=(x²+y²)/(x+y)²+(2/xy)×[x²y²/(x+y)²]
=(x²+y²)/(x+y)²+2xy/(x+y)²
=(x²+2xy+y²)/(x+y)²
=(x+y)²/(x+y)²
=1

内项积等于外项积
所以5(5x-33)=7(6x-60)
5×5x-5×33=7×6x-7×60
25x-165=42x-420
42x-25x=420-165
17x=255
x=255÷17
x=15