展开 (x-3)(x-(3+i))(x-(3-i))

解答

展开

(x - 3) (x - (3 + i)) (x - (3 - i))

x^{3} - 9 x^{2} + 28 x - 30

求解步骤

(x - 3) (x - (3 + i)) (x - (3 - i))

展开

(x - 3) (x - (3 + i)) (x - (3 - i)) : (3 i + x^{2} - 6 x - x i + 9) (x - (3 - i))

= (3 i + x^{2} - 6 x - x i + 9) (x - (3 - i))

打开括号

= 3 i x + 3 i (- (3 - i)) + x^{2} x + x^{2} (- (3 - i)) - 6 xx - 6 x (- (3 - i)) - x i x - x i (- (3 - i)) + 9 x + 9 (- (3 - i))

化简

3 i x + 3 i (- (3 - i)) + x^{2} x + x^{2} (- (3 - i)) - 6 xx - 6 x (- (3 - i)) - x i x - x i (- (3 - i)) + 9 x + 9 (- (3 - i)) : x^{3} - 9 x^{2} + 28 x - 30

= x^{3} - 9 x^{2} + 28 x - 30

e x p an d \frac{2 ( 8 x + 7 )}{( 3 x - 1 ) ^{3}}

e x p an d K + 0.082 K

s im pl i f y (3 x + 5) 2

e x p an d (t + 1) d t

e x p an d (cot (x) + 1) (3 cot (x) + 1 = 0)