6/x+(140-x)/16=15 x等于多少?

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6/x+(140-x)/16=15x等于多少?6/x+(140-x)/16=15x等于多少?6/x+(140-x)/16=15x等于多少?(6*16+140x-x^2)/16x=1596+140x-x

6/x+(140-x)/16=15 x等于多少?
6/x+(140-x)/16=15 x等于多少?

6/x+(140-x)/16=15 x等于多少?
(6*16+140x-x^2)/16x=15
96+140x-x^2=240x
x^2+100x-96=0
∴ x=(-100+-√100^2+4*1*96)/2
=(-100+-√10384)/2
=(-100+-√16*649)/2
=-50+-2√649 (√表示根号2)

6/x+(140-x)/16=15 去分母得
96+(140-x)x=240x,
即x^2+100x-96=0,
x=-50±2√649