展开 ((x-b)^2)/(x^3)

解答

展开

\frac{( x - b ) ^{2}}{x ^{3}}

\frac{1}{x} - \frac{2 b}{x ^{2}} + \frac{b ^{2}}{x ^{3}}

求解步骤

\frac{( x - b ) ^{2}}{x ^{3}}

(x - b)^{2} = x^{2} - 2 b x + b^{2}

= \frac{x ^{2} - 2 b x + b ^{2}}{x ^{3}}

使用分式法则:

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

\frac{x ^{2} - 2 x b + b ^{2}}{x ^{3}} = \frac{x ^{2}}{x ^{3}} - \frac{2 x b}{x ^{3}} + \frac{b ^{2}}{x ^{3}}

= \frac{x ^{2}}{x ^{3}} - \frac{2 b x}{x ^{3}} + \frac{b ^{2}}{x ^{3}}

消掉

\frac{x ^{2}}{x ^{3}} : \frac{1}{x}

= \frac{1}{x} - \frac{2 b x}{x ^{3}} + \frac{b ^{2}}{x ^{3}}

消掉

\frac{2 x b}{x ^{3}} : \frac{2 b}{x ^{2}}

= \frac{1}{x} - \frac{2 b}{x ^{2}} + \frac{b ^{2}}{x ^{3}}

e x p an d n (n - 3 n^{2} = 2)

e x p an d \frac{3}{4 ( 12 v + 16 )}

e x p an d \frac{( 2 x ^{3} + 3 ) ^{6}}{x ^{12}}

e x p an d (A + Bt) e^{s t}

e x p an d (12 - - 12 - i) 28