Whakaoti i te 7-4x-x^2

$$7-4x- { x }^{ 2 }$$

Tauwehe

$$-\left(x-\left(-\sqrt{11}-2\right)\right)\left(x-\left(\sqrt{11}-2\right)\right)$$

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

Ka taea te huamaha pūrua te tauwehe mā te whakamahi i te huringa ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), ina ko x_{1} me x_{2} ngā otinga o te whārite pūrua ax^{2}+bx+c=0.

$$-x^{2}-4x+7=0$$

Ko ngā whārite katoa o te āhua ax^{2}+bx+c=0 ka taea te whakaoti mā te whakamahi i te tikanga tātai pūrua: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. E rua ngā otinga ka puta i te tikanga tātai pūrua, ko tētahi ina he tāpiri a ±, ā, ko tētahi ina he tango.

$$x=\frac{-\left(-4\right)±\sqrt{\left(-4\right)^{2}-4\left(-1\right)\times 7}}{2\left(-1\right)}$$

Pūrua -4.

$$x=\frac{-\left(-4\right)±\sqrt{16-4\left(-1\right)\times 7}}{2\left(-1\right)}$$

Whakareatia -4 ki te -1.

$$x=\frac{-\left(-4\right)±\sqrt{16+4\times 7}}{2\left(-1\right)}$$

Whakareatia 4 ki te 7.

$$x=\frac{-\left(-4\right)±\sqrt{16+28}}{2\left(-1\right)}$$

Tāpiri 16 ki te 28.

$$x=\frac{-\left(-4\right)±\sqrt{44}}{2\left(-1\right)}$$

Tuhia te pūtakerua o te 44.

$$x=\frac{-\left(-4\right)±2\sqrt{11}}{2\left(-1\right)}$$

Ko te tauaro o -4 ko 4.

$$x=\frac{4±2\sqrt{11}}{2\left(-1\right)}$$

Whakareatia 2 ki te -1.

$$x=\frac{4±2\sqrt{11}}{-2}$$

Nā, me whakaoti te whārite x=\frac{4±2\sqrt{11}}{-2} ina he tāpiri te ±. Tāpiri 4 ki te 2\sqrt{11}.

$$x=\frac{2\sqrt{11}+4}{-2}$$

Whakawehe 4+2\sqrt{11} ki te -2.

$$x=-\left(\sqrt{11}+2\right)$$

Nā, me whakaoti te whārite x=\frac{4±2\sqrt{11}}{-2} ina he tango te ±. Tango 2\sqrt{11} mai i 4.

$$x=\frac{4-2\sqrt{11}}{-2}$$

Whakawehe 4-2\sqrt{11} ki te -2.

$$x=\sqrt{11}-2$$

Tauwehea te kīanga taketake mā te whakamahi i te ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right). Me whakakapi te -\left(2+\sqrt{11}\right) mō te x_{1} me te -2+\sqrt{11} mō te x_{2}.

$$-x^{2}-4x+7=-\left(x-\left(-\left(\sqrt{11}+2\right)\right)\right)\left(x-\left(\sqrt{11}-2\right)\right)$$

Aromātai

$$7-4x-x^{2}$$