展开 ((25-5x)(x+1))/(2x)

解答

展开

\frac{( 25 - 5 x ) ( x + 1 )}{2 x}

- \frac{5 x}{2} + 10 + \frac{25}{2 x}

求解步骤

\frac{( 25 - 5 x ) ( x + 1 )}{2 x}

乘开

(25 - 5 x) (x + 1) : - 5 x^{2} + 20 x + 25

= \frac{- 5 x ^{2} + 20 x + 25}{2 x}

使用分式法则:

\frac{a \pm b}{c} = \frac{a}{c} \pm \frac{b}{c}

\frac{- 5 x ^{2} + 20 x + 25}{2 x} = - \frac{5 x ^{2}}{2 x} + \frac{20 x}{2 x} + \frac{25}{2 x}

= - \frac{5 x ^{2}}{2 x} + \frac{20 x}{2 x} + \frac{25}{2 x}

消掉

\frac{5 x ^{2}}{2 x} : \frac{5 x}{2}

= - \frac{5 x}{2} + \frac{20 x}{2 x} + \frac{25}{2 x}

消掉

\frac{20 x}{2 x} : 10

= - \frac{5 x}{2} + 10 + \frac{25}{2 x}

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