展开 (3x^2+9x-5)/(12)

解答

展开

\frac{3 x ^{2} + 9 x - 5}{12}

\frac{x ^{2}}{4} + \frac{3 x}{4} - \frac{5}{12}

求解步骤

\frac{3 x ^{2} + 9 x - 5}{12}

使用分式法则:

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

\frac{3 x ^{2} + 9 x - 5}{12} = \frac{3 x ^{2}}{12} + \frac{9 x}{12} - \frac{5}{12}

= \frac{3 x ^{2}}{12} + \frac{9 x}{12} - \frac{5}{12}

消掉

\frac{3 x ^{2}}{12} : \frac{x ^{2}}{4}

= \frac{x ^{2}}{4} + \frac{9 x}{12} - \frac{5}{12}

消掉

\frac{9 x}{12} : \frac{3 x}{4}

= \frac{x ^{2}}{4} + \frac{3 x}{4} - \frac{5}{12}

e x p an d \frac{( 3 + x ) ^{2} - 3 y ( 2 x - 3 ) - 18 y ^{2}}{2 x ^{2}}

e x p an d 24 e^{- 30 t} + 30 (\frac{4}{5} - \frac{4}{5} e^{- 30 t})

e x p an d \frac{x ^{3}}{2 ( x + 1 ) ^{2}}

e x p an d d y (x sin (y) + y cos (x) + g y)

e x p an d \frac{1 - x + 3 x ^{2}}{( 1 - 4 x + 3 x ^{2} ) ( 1 - x )}