化简 (2/7-1/x)*(5/x+1/3)

解答

化简

(\frac{2}{7} - \frac{1}{x}) \cdot (\frac{5}{x} + \frac{1}{3})

\frac{( 2 x - 7 ) ( 15 + x )}{21 x ^{2}}

求解步骤

(\frac{2}{7} - \frac{1}{x}) (\frac{5}{x} + \frac{1}{3})

合并

\frac{2}{7} - \frac{1}{x} : \frac{2 x - 7}{7 x}

= \frac{2 x - 7}{7 x} (\frac{5}{x} + \frac{1}{3})

使用分式法则:

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

= \frac{( 2 x - 7 ) ( \frac{5}{x} + \frac{1}{3} )}{7 x}

化简

(2 x - 7) (\frac{5}{x} + \frac{1}{3}) : \frac{( 2 x - 7 ) ( 15 + x )}{3 x}

= \frac{\frac{( 2 x - 7 ) ( 15 + x )}{3 x}}{7 x}

使用分式法则:

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

= \frac{( 2 x - 7 ) ( 15 + x )}{3 x \cdot 7 x}

化简

3 x \cdot 7 x : 21 x^{2}

= \frac{( 2 x - 7 ) ( 15 + x )}{21 x ^{2}}

s im pl i f y 4 ((\frac{19}{12})^{\frac{1}{24}} - 1)

s im pl i f y (x - 3) (x - 5)

e x p an d (vx + x x^{2} - v^{2}) d x - x (H (x) d x + x d v = 0)

e x p an d cos (x) \cdot (48 x + 24)

e x p an d - \frac{10 ( 3 + 3 )}{3}