展开 (2/3 a-1/3 b)^2

解答

展开

(\frac{2}{3} a - \frac{1}{3} b)^{2}

\frac{4 a ^{2} - 4 ab + b ^{2}}{9}

求解步骤

(\frac{2}{3} a - \frac{1}{3} b)^{2}

使用完全平方公式:

(a - b)^{2} = a^{2} - 2 ab + b^{2}

(\frac{2}{3} a - \frac{1}{3} b)^{2} = (\frac{2}{3} a)^{2} - 2 \cdot \frac{2}{3} a \frac{1}{3} b + (\frac{1}{3} b)^{2}

= (\frac{2}{3} a)^{2} - 2 \cdot \frac{2}{3} a \frac{1}{3} b + (\frac{1}{3} b)^{2}

化简

(\frac{2}{3} a)^{2} - 2 \cdot \frac{2}{3} a \frac{1}{3} b + (\frac{1}{3} b)^{2} : \frac{4 a ^{2} - 4 ab + b ^{2}}{9}

= \frac{4 a ^{2} - 4 ab + b ^{2}}{9}

s im pl i f y (x - \frac{1}{a}) (x - \frac{1}{b}) (x - \frac{1}{c})

e x p an d \frac{( x ^{2} - 2 x + 3 ) ( 2 x + 3 )}{( x - 2 ) ( x + 5 )}

e x p an d so l v e (30 - 2 h) (30 - h) (h)

e x p an d (3 x) l e f t (- 118.33 x - 10 x^{2})

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