Whakaoti i te 2x^2-2x-12

$$2 x ^ { 2 } - 2 x - 12$$

Tauwehe

$$2\left(x-3\right)\left(x+2\right)$$

Ngā Upane Otinga

Tauwehea te 2.

$$2\left(x^{2}-x-6\right)$$

Whakaarohia te x^{2}-x-6. Whakatauwehea te kīanga mā te whakarōpū. Tuatahi, me tuhi anō te kīanga hei x^{2}+ax+bx-6. Hei kimi a me b, whakaritea tētahi pūnaha kia whakaoti.

$$a+b=-1 ab=1\left(-6\right)=-6$$

I te mea kua tōraro te ab, he tauaro ngā tohu o a me b. I te mea kua tōraro te a+b, he nui ake te uara pū o te tau tōraro i tō te tōrunga. Whakarārangitia ngā tau tōpū takirua pērā katoa ka hoatu i te hua -6.

$$1,-6 2,-3$$

Tātaihia te tapeke mō ia takirua.

$$1-6=-5 2-3=-1$$

Ko te otinga te takirua ka hoatu i te tapeke -1.

$$a=-3 b=2$$

Tuhia anō te x^{2}-x-6 hei \left(x^{2}-3x\right)+\left(2x-6\right).

$$\left(x^{2}-3x\right)+\left(2x-6\right)$$

Tauwehea te x i te tuatahi me te 2 i te rōpū tuarua.

$$x\left(x-3\right)+2\left(x-3\right)$$

Whakatauwehea atu te kīanga pātahi x-3 mā te whakamahi i te āhuatanga tātai tohatoha.

$$\left(x-3\right)\left(x+2\right)$$

Me tuhi anō te kīanga whakatauwehe katoa.

$$2\left(x-3\right)\left(x+2\right)$$

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.

$$2x^{2}-2x-12=0$$

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.

$$x=\frac{-\left(-2\right)±\sqrt{\left(-2\right)^{2}-4\times 2\left(-12\right)}}{2\times 2}$$

Pūrua -2.

$$x=\frac{-\left(-2\right)±\sqrt{4-4\times 2\left(-12\right)}}{2\times 2}$$

Whakareatia -4 ki te 2.

$$x=\frac{-\left(-2\right)±\sqrt{4-8\left(-12\right)}}{2\times 2}$$

Whakareatia -8 ki te -12.

$$x=\frac{-\left(-2\right)±\sqrt{4+96}}{2\times 2}$$

Tāpiri 4 ki te 96.

$$x=\frac{-\left(-2\right)±\sqrt{100}}{2\times 2}$$

Tuhia te pūtakerua o te 100.

$$x=\frac{-\left(-2\right)±10}{2\times 2}$$

Ko te tauaro o -2 ko 2.

$$x=\frac{2±10}{2\times 2}$$

Whakareatia 2 ki te 2.

$$x=\frac{2±10}{4}$$

Nā, me whakaoti te whārite x=\frac{2±10}{4} ina he tāpiri te ±. Tāpiri 2 ki te 10.

$$x=\frac{12}{4}$$

Whakawehe 12 ki te 4.

$$x=3$$

Nā, me whakaoti te whārite x=\frac{2±10}{4} ina he tango te ±. Tango 10 mai i 2.

$$x=-\frac{8}{4}$$

Whakawehe -8 ki te 4.

$$x=-2$$

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 3 mō te x_{1} me te -2 mō te x_{2}.

$$2x^{2}-2x-12=2\left(x-3\right)\left(x-\left(-2\right)\right)$$

Whakamāmātia ngā kīanga katoa o te āhua p-\left(-q\right) ki te p+q.

$$2x^{2}-2x-12=2\left(x-3\right)\left(x+2\right)$$

Aromātai

$$2\left(x-3\right)\left(x+2\right)$$