化简 (7x-1)-(2x^2+4x+7)

解答

化简

(7 x - 1) - (2 x^{2} + 4 x + 7)

- 2 x^{2} + 3 x - 8

求解步骤

(7 x - 1) - (2 x^{2} + 4 x + 7)

使用法则:

(a) = a

(7 x - 1) = 7 x - 1

= 7 x - 1 - (2 x^{2} + 4 x + 7)

使用分配律:

- (a + b) = - a - b

- (2 x^{2} + 4 x + 7) = - 2 x^{2} - 4 x - 7

= 7 x - 1 - 2 x^{2} - 4 x - 7

对同类项分组

= - 2 x^{2} + 7 x - 4 x - 1 - 7

\frac{7}{8} \div \frac{21}{16}

s im pl i f y 2 (6 + 12)

e x p an d (x - 5) (4 x^{2} - 2 x + 1)

s im pl i f y 4 (8 x + 1) - 6 (1 - 8 x)

s im pl i f y \frac{1}{1 + 4 i} + \frac{1}{1 + 5 i}