展开 2((1-4y)/3)^2

解答

展开

2 (\frac{1 - 4 y}{3})^{2}

\frac{32 y ^{2}}{9} - \frac{16 y}{9} + \frac{2}{9}

求解步骤

2 (\frac{1 - 4 y}{3})^{2}

(\frac{1 - 4 y}{3})^{2} = \frac{1 - 8 y + 16 y ^{2}}{3 ^{2}}

= 2 \cdot \frac{16 y ^{2} - 8 y + 1}{3 ^{2}}

分式相乘:

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

= \frac{( 1 - 8 y + 16 y ^{2} ) \cdot 2}{3 ^{2}}

3^{2} = 9

= \frac{2 ( 16 y ^{2} - 8 y + 1 )}{9}

乘开

(1 - 8 y + 16 y^{2}) \cdot 2 : 2 - 16 y + 32 y^{2}

= \frac{2 - 16 y + 32 y ^{2}}{9}

使用分式法则:

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

\frac{2 - 16 y + 32 y ^{2}}{9} = \frac{2}{9} - \frac{16 y}{9} + \frac{32 y ^{2}}{9}

= \frac{2}{9} - \frac{16 y}{9} + \frac{32 y ^{2}}{9}

改写为标准形式

= \frac{32 y ^{2}}{9} - \frac{16 y}{9} + \frac{2}{9}

e x p an d \frac{5 x - 11}{( x + 1 ) ( x + 5 )}

e x p an d x (x - 1) (x + Δ x (x + Δ x - 1))

e x p an d - 3 (6 x + 3 = - 18 x + 9)

e x p an d (3 x + 1) + (- 7 x + 9)

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