化简 (9x^2-9x-7)-(x^2-6x-2)

解答

化简

(9 x^{2} - 9 x - 7) - (x^{2} - 6 x - 2)

8 x^{2} - 3 x - 5

求解步骤

(9 x^{2} - 9 x - 7) - (x^{2} - 6 x - 2)

使用法则:

(a) = a

(9 x^{2} - 9 x - 7) = 9 x^{2} - 9 x - 7

= 9 x^{2} - 9 x - 7 - (x^{2} - 6 x - 2)

使用分配律:

- (a - b) = - a + b

- (x^{2} - 6 x - 2) = - x^{2} + 6 x + 2

= 9 x^{2} - 9 x - 7 - x^{2} + 6 x + 2

对同类项分组

= 9 x^{2} - x^{2} - 9 x + 6 x - 7 + 2

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

s im pl i f y 6 n^{2} - 2 n - 3 + 5 n^{2} - 9 n - 6

s im pl i f y \frac{4 - x ^{2}}{x ^{2} - 4 x + 4}

s im pl i f y (- 10 x^{2} + 4 x) - (- 4 x^{2} + 6 x + 8)

s im pl i f y 16 (x + y)^{2} - 25 (x - 2 y)^{2}