Whakaoti i te -3x^2-15x-21

$$- 3 x ^ { 2 } - 15 x - 21$$

Tauwehe

$$3\left(-x^{2}-5x-7\right)$$

Ngā Upane Otinga

Tauwehea te 3. Kāore te pūrau -x^{2}-5x-7 i whakatauwehea i te mea kāhore ōna pūtake whakahau.

$$3\left(-x^{2}-5x-7\right)$$

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.

$$-3x^{2}-15x-21=0$$

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.

$$x=\frac{-\left(-15\right)±\sqrt{\left(-15\right)^{2}-4\left(-3\right)\left(-21\right)}}{2\left(-3\right)}$$

Pūrua -15.

$$x=\frac{-\left(-15\right)±\sqrt{225-4\left(-3\right)\left(-21\right)}}{2\left(-3\right)}$$

Whakareatia -4 ki te -3.

$$x=\frac{-\left(-15\right)±\sqrt{225+12\left(-21\right)}}{2\left(-3\right)}$$

Whakareatia 12 ki te -21.

$$x=\frac{-\left(-15\right)±\sqrt{225-252}}{2\left(-3\right)}$$

Tāpiri 225 ki te -252.

$$x=\frac{-\left(-15\right)±\sqrt{-27}}{2\left(-3\right)}$$

Tā te mea e kore te pūrua o tētahi tau tōraro e tautohutia ki te āpure tūturu, kāhore he rongoā. Kāore e taea te pūrau pūrua te whakatauwehe.

$$-3x^{2}-15x-21$$

Aromātai

$$-3x^{2}-15x-21$$