展开 (2m-3n)^3

解答

展开

(2 m - 3 n)^{3}

8 m^{3} - 36 m^{2} n + 54 m n^{2} - 27 n^{3}

求解步骤

(2 m - 3 n)^{3}

使用完全立方公式:

(a - b)^{3} = a^{3} - 3 a^{2} b + 3 a b^{2} - b^{3}

(2 m - 3 n)^{3} = (2 m)^{3} - 3 (2 m)^{2} \cdot 3 n + 3 \cdot 2 m (3 n)^{2} - (3 n)^{3}

= (2 m)^{3} - 3 (2 m)^{2} \cdot 3 n + 3 \cdot 2 m (3 n)^{2} - (3 n)^{3}

化简

(2 m)^{3} - 3 (2 m)^{2} \cdot 3 n + 3 \cdot 2 m (3 n)^{2} - (3 n)^{3} : 8 m^{3} - 36 m^{2} n + 54 m n^{2} - 27 n^{3}

= 8 m^{3} - 36 m^{2} n + 54 m n^{2} - 27 n^{3}

e x p an d (a + 3 b) (2 a - 5 b)

s im pl i f y lo g_{4} (2) + lo g_{4} (512)

s im pl i f y (7 - 9) (- - 80)

s im pl i f y \frac{sin ( θ )}{csc ( θ )} + \frac{cos ( θ )}{sec ( θ )}

f a c t or 20 x^{5} + 18 x^{4}