展开 2t^4e^{-2t}+[U^4(t)(t-3)]

解答

展开

2 t^{4} e^{- 2 t} + [U^{4} (t) (t - 3)]

2 e^{- 2 t} t^{4} + t^{2} U^{4} - 3 t U^{4}

求解步骤

2 t^{4} e^{- 2 t} + (U^{4} (t) (t - 3))

去除括号:

(a) = a

= 2 t^{4} e^{- 2 t} + U^{4} t (t - 3)

= 2 e^{- 2 t} t^{4} + t U^{4} (t - 3)

乘开

U^{4} t (t - 3) : t^{2} U^{4} - 3 t U^{4}

= 2 t^{4} e^{- 2 t} + t^{2} U^{4} - 3 t U^{4}

e x p an d sin ((4 n + 3) \cdot 9 0^{\circ})

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

e x p an d (A + B = 1,) - (- 2 A + B = - 1)

e x p an d \frac{6}{x} + \frac{9}{2} x

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