展开 (y(3-y)^2)/2

解答

展开

\frac{y ( 3 - y ) ^{2}}{2}

\frac{y ^{3}}{2} - 3 y^{2} + \frac{9 y}{2}

求解步骤

\frac{y ( 3 - y ) ^{2}}{2}

(3 - y)^{2} = 9 - 6 y + y^{2}

= \frac{y ( y ^{2} - 6 y + 9 )}{2}

乘开

y (9 - 6 y + y^{2}) : 9 y - 6 y^{2} + y^{3}

= \frac{9 y - 6 y ^{2} + y ^{3}}{2}

使用分式法则:

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

\frac{9 y - 6 y ^{2} + y ^{3}}{2} = \frac{9 y}{2} - \frac{6 y ^{2}}{2} + \frac{y ^{3}}{2}

= \frac{9 y}{2} - \frac{6 y ^{2}}{2} + \frac{y ^{3}}{2}

数字相除:

\frac{6}{2} = 3

= \frac{9 y}{2} - 3 y^{2} + \frac{y ^{3}}{2}

改写为标准形式

= \frac{y ^{3}}{2} - 3 y^{2} + \frac{9 y}{2}

e x p an d \frac{( 2 + x ) ( 7 - x )}{( 5 - x ) ( 4 + x )}

e x p an d \frac{6 ( x + h )}{( x + h ) + 2}

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

e x p an d \frac{5 ( x + 2 )}{12}

e x p an d - 3 (1 + 6 x = 14 + x)