展开-((m+n)^2)/4

解答

展开

- \frac{( m + n ) ^{2}}{4}

- \frac{m ^{2}}{4} - \frac{mn}{2} - \frac{n ^{2}}{4}

求解步骤

- \frac{( m + n ) ^{2}}{4}

(m + n)^{2} = m^{2} + 2 mn + n^{2}

= - \frac{m ^{2} + 2 mn + n ^{2}}{4}

使用分式法则:

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

\frac{m ^{2} + 2 mn + n ^{2}}{4} = - (\frac{m ^{2}}{4}) - (\frac{2 mn}{4}) - (\frac{n ^{2}}{4})

= - (\frac{m ^{2}}{4}) - (\frac{2 mn}{4}) - (\frac{n ^{2}}{4})

去除括号:

(a) = a

= - \frac{m ^{2}}{4} - \frac{2 mn}{4} - \frac{n ^{2}}{4}

消掉

\frac{2 mn}{4} : \frac{mn}{2}

= - \frac{m ^{2}}{4} - \frac{mn}{2} - \frac{n ^{2}}{4}

e x p an d \frac{( r x H - x q y ) H}{G}

e x p an d (6 x y^{3} + cos (y)) d y

e x p an d \frac{8}{( s + 2 ) ^{2} ( s ^{2} + 4 )}

e x p an d e^{4 x} (e^{2 x} - 4 + e^{5 x})

e x p an d - 1 (26 x - 21 y - 69 z = 436)