簡約 x^2(x+4)+3x(x+4)-70(x+4)

解

簡約

x^{2} (x + 4) + 3 x (x + 4) - 70 (x + 4)

x^{3} + 7 x^{2} - 58 x - 280

解答ステップ

x^{2} (x + 4) + 3 x (x + 4) - 70 (x + 4)

拡張

x^{2} (x + 4) : x^{3} + 4 x^{2}

= x^{3} + 4 x^{2} + 3 x (x + 4) - 70 (x + 4)

拡張

3 x (x + 4) : 3 x^{2} + 12 x

= x^{3} + 4 x^{2} + 3 x^{2} + 12 x - 70 (x + 4)

拡張

- 70 (x + 4) : - 70 x - 280

= x^{3} + 4 x^{2} + 3 x^{2} + 12 x - 70 x - 280

類似した元を足す:

4 x^{2} + 3 x^{2} = 7 x^{2}

= x^{3} + 7 x^{2} + 12 x - 70 x - 280

類似した元を足す:

12 x - 70 x = - 58 x

= x^{3} + 7 x^{2} - 58 x - 280