展开 ((18n-7)^2)/(441)

解答

展开

\frac{( 18 n - 7 ) ^{2}}{441}

\frac{36 n ^{2}}{49} - \frac{4 n}{7} + \frac{1}{9}

求解步骤

\frac{( 18 n - 7 ) ^{2}}{441}

(18 n - 7)^{2} = 324 n^{2} - 252 n + 49

= \frac{324 n ^{2} - 252 n + 49}{441}

使用分式法则:

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

\frac{324 n ^{2} - 252 n + 49}{441} = \frac{324 n ^{2}}{441} - \frac{252 n}{441} + \frac{49}{441}

= \frac{324 n ^{2}}{441} - \frac{252 n}{441} + \frac{49}{441}

消掉

\frac{324 n ^{2}}{441} : \frac{36 n ^{2}}{49}

= \frac{36 n ^{2}}{49} - \frac{252 n}{441} + \frac{49}{441}

消掉

\frac{252 n}{441} : \frac{4 n}{7}

= \frac{36 n ^{2}}{49} - \frac{4 n}{7} + \frac{49}{441}

消掉

\frac{49}{441} : \frac{1}{9}

= \frac{36 n ^{2}}{49} - \frac{4 n}{7} + \frac{1}{9}

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

\frac{d}{d y} ((x (y)) (\frac{y ^{4}}{4} + \frac{1}{8 y ^{2}}))

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

e x p an d \frac{d ^{2}}{d ^{2} x} (y^{4} + 3 y - 4 x^{3} = 5 x + 1)

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