展开 ((-4x^2+7x+2)(x+1))/2

解答

展开

\frac{( - 4 x ^{2} + 7 x + 2 ) ( x + 1 )}{2}

- 2 x^{3} + \frac{3 x ^{2}}{2} + \frac{9 x}{2} + 1

求解步骤

\frac{( - 4 x ^{2} + 7 x + 2 ) ( x + 1 )}{2}

乘开

(- 4 x^{2} + 7 x + 2) (x + 1) : - 4 x^{3} + 3 x^{2} + 9 x + 2

= \frac{- 4 x ^{3} + 3 x ^{2} + 9 x + 2}{2}

使用分式法则:

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

\frac{- 4 x ^{3} + 3 x ^{2} + 9 x + 2}{2} = - \frac{4 x ^{3}}{2} + \frac{3 x ^{2}}{2} + \frac{9 x}{2} + \frac{2}{2}

= - \frac{4 x ^{3}}{2} + \frac{3 x ^{2}}{2} + \frac{9 x}{2} + \frac{2}{2}

使用法则

\frac{a}{a} = 1

\frac{2}{2} = 1

= - \frac{4 x ^{3}}{2} + \frac{3 x ^{2}}{2} + \frac{9 x}{2} + 1

数字相除:

\frac{4}{2} = 2

= - 2 x^{3} + \frac{3 x ^{2}}{2} + \frac{9 x}{2} + 1

e x p an d \frac{( b - a ) ( a + b )}{2}

e x p an d \frac{14 v ( 6 v - 5 )}{3}

e x p an d \frac{( 11 x ^{4} + 2 ) ^{5}}{2}

e x p an d (x_{0} + e x_{1} + x_{2} e^{2})^{3}

\frac{d}{d x} ((z) (2 x^{2} + 3 y^{2} + 5 z^{2} - 9))