展开 (D+6)(5x-(D-4)=0)

解答

展开

(D + 6) (5 x - (D - 4) = 0)

5 D x - D^{2} + 4 D = 0

求解步骤

(D + 6) (5 x - (D - 4) = 0)

= (D + 6) (5 x - 0 = (D - 4))

使用 FOIL 方法:

(a + b) (c + d) = a c + a d + b c + b d

a = D, b = 6, c = 5 x, d = - (D - 4) = 0

= D \cdot 5 x + D (- (D - 4) = 0) + 6 \cdot 5 x + 6 (- (D - 4) = 0)

使用加减运算法则

+ (- a) = - a

5 D x - D (D - 4) = 0 + 6 \cdot 5 x - 6 (D - 4) = 0

乘开

5 D x - D (D - 4) : 5 D x - D^{2} + 4 D

5 D x - D^{2} + 4 D = 0

e x p an d \frac{A ( x ) B ( y )}{( x + y ) ^{2}}

e x p an d x^{2} y^{''} (x) - x y^{'} (x) + (1 - x) y

s im pl i f y (x - 5)^{2} (x - 5 + 2 i) (x + i)

s im pl i f y (2 p + q) (2 p - q)

e x p an d A (- 14, 11) B (10, - 9) C (- 13, - 4)