展开 (m^2-2mn-8n^2)(m^3-3m^2n+2,mn^2)

解答

展开

(m^{2} - 2 mn - 8 n^{2}) (m^{3} - 3 m^{2} n + 2, m n^{2})

m^{3} m^{2} - 3 m^{2} m^{2} n + 2 m^{2}, m n^{2} - 2 m^{3} mn + 2 \cdot 3 m^{2} mnn - 2 \cdot 2 mn, m n^{2} - 8 m^{3} n^{2} + 8 \cdot 3 m^{2} n^{2} n - 8 \cdot 2 n^{2}, m n^{2}

求解步骤

(m^{2} - 2 mn - 8 n^{2}) (m^{3} - 3 m^{2} n + 2, m n^{2})

打开括号

= m^{2} m^{3} + m^{2} (- 3 m^{2} n) + m^{2} \cdot 2, m n^{2} + (- 2 mn) m^{3} + (- 2 mn) (- 3 m^{2} n) + (- 2 mn) \cdot 2, m n^{2} + (- 8 n^{2}) m^{3} + (- 8 n^{2}) (- 3 m^{2} n) + (- 8 n^{2}) \cdot 2, m n^{2}

使用加减运算法则

+ (- a) = - a, (- a) (- b) = ab

= m^{3} m^{2} - 3 m^{2} m^{2} n + 2 m^{2}, m n^{2} - 2 m^{3} mn + 2 \cdot 3 m^{2} mnn - 2 \cdot 2 mn, m n^{2} - 8 m^{3} n^{2} + 8 \cdot 3 m^{2} n^{2} n - 8 \cdot 2 n^{2}, m n^{2}

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

s im pl i f y 2 x (x^{3} - 3 x + 7)

e x p an d (\frac{f}{2} (l - x)) (\frac{w x}{2} (l - x))

e x p an d 3 (6 x + 9 y)^{2} (6 + 9 y^{'} (x))

s im pl i f y (a^{2} + b^{2} + c^{2} + d^{2})^{2}