簡約 (2x+20-6x^2)-(4-7x^2+12x)

解

簡約

(2 x + 20 - 6 x^{2}) - (4 - 7 x^{2} + 12 x)

x^{2} - 10 x + 16

解答ステップ

(2 x + 20 - 6 x^{2}) - (4 - 7 x^{2} + 12 x)

規則を適用する:

(a) = a

(2 x + 20 - 6 x^{2}) = 2 x + 20 - 6 x^{2}

= 2 x + 20 - 6 x^{2} - (4 - 7 x^{2} + 12 x)

分配法則を適用する:

- (a - b) = - a + b

- (4 - 7 x^{2} + 12 x) = - 4 + 7 x^{2} - 12 x

= 2 x + 20 - 6 x^{2} - 4 + 7 x^{2} - 12 x

条件のようなグループ

= - 6 x^{2} + 7 x^{2} + 2 x - 12 x + 20 - 4

類似した元を足す:

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

= x^{2} + 2 x - 12 x + 20 - 4

類似した元を足す:

2 x - 12 x = - 10 x

= x^{2} - 10 x + 20 - 4

数を引く:

20 - 4 = 16

= x^{2} - 10 x + 16