Whakaoti i te x^2+121x+120=

$$x ^ { 2 } + 121 x + 120 =$$

Tauwehe

$$\left(x+1\right)\left(x+120\right)$$

Ngā Upane Otinga

Whakatauwehea te kīanga mā te whakarōpū. Tuatahi, me tuhi anō te kīanga hei x^{2}+ax+bx+120. Hei kimi a me b, whakaritea tētahi pūnaha kia whakaoti.

$$a+b=121 ab=1\times 120=120$$

I te mea kua tōrunga te ab, he ōrite te tohu o a me b. I te mea kua tōrunga te a+b, he tōrunga hoki a a me b. Whakarārangitia ngā tau tōpū takirua pērā katoa ka hoatu i te hua 120.

$$1,120 2,60 3,40 4,30 5,24 6,20 8,15 10,12$$

Tātaihia te tapeke mō ia takirua.

$$1+120=121 2+60=62 3+40=43 4+30=34 5+24=29 6+20=26 8+15=23 10+12=22$$

Ko te otinga te takirua ka hoatu i te tapeke 121.

$$a=1 b=120$$

Tuhia anō te x^{2}+121x+120 hei \left(x^{2}+x\right)+\left(120x+120\right).

$$\left(x^{2}+x\right)+\left(120x+120\right)$$

Tauwehea te x i te tuatahi me te 120 i te rōpū tuarua.

$$x\left(x+1\right)+120\left(x+1\right)$$

Whakatauwehea atu te kīanga pātahi x+1 mā te whakamahi i te āhuatanga tātai tohatoha.

$$\left(x+1\right)\left(x+120\right)$$

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.

$$x^{2}+121x+120=0$$

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.

$$x=\frac{-121±\sqrt{121^{2}-4\times 120}}{2}$$

Pūrua 121.

$$x=\frac{-121±\sqrt{14641-4\times 120}}{2}$$

Whakareatia -4 ki te 120.

$$x=\frac{-121±\sqrt{14641-480}}{2}$$

Tāpiri 14641 ki te -480.

$$x=\frac{-121±\sqrt{14161}}{2}$$

Tuhia te pūtakerua o te 14161.

$$x=\frac{-121±119}{2}$$

Nā, me whakaoti te whārite x=\frac{-121±119}{2} ina he tāpiri te ±. Tāpiri -121 ki te 119.

$$x=-\frac{2}{2}$$

Whakawehe -2 ki te 2.

$$x=-1$$

Nā, me whakaoti te whārite x=\frac{-121±119}{2} ina he tango te ±. Tango 119 mai i -121.

$$x=-\frac{240}{2}$$

Whakawehe -240 ki te 2.

$$x=-120$$

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 -1 mō te x_{1} me te -120 mō te x_{2}.

$$x^{2}+121x+120=\left(x-\left(-1\right)\right)\left(x-\left(-120\right)\right)$$

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

$$x^{2}+121x+120=\left(x+1\right)\left(x+120\right)$$

Aromātai

$$\left(x+1\right)\left(x+120\right)$$