化简 (10x^2-7x+7)-(4x^2+5x-9)

解答

化简

(10 x^{2} - 7 x + 7) - (4 x^{2} + 5 x - 9)

6 x^{2} - 12 x + 16

求解步骤

(10 x^{2} - 7 x + 7) - (4 x^{2} + 5 x - 9)

使用法则:

(a) = a

(10 x^{2} - 7 x + 7) = 10 x^{2} - 7 x + 7

= 10 x^{2} - 7 x + 7 - (4 x^{2} + 5 x - 9)

使用分配律:

- (a + b) = - a - b

- (4 x^{2} + 5 x - 9) = - 4 x^{2} - 5 x + 9

= 10 x^{2} - 7 x + 7 - 4 x^{2} - 5 x + 9

对同类项分组

= 10 x^{2} - 4 x^{2} - 7 x - 5 x + 7 + 9

s im pl i f y 12 + 7

s im pl i f y (- 8 x^{2} + 3) + (x^{2} + 3 x - 8)

e x p an d b (a - 6)

s im pl i f y 8 d - 4 - d - 2

s im pl i f y - 18 - 7