Whakaoti i te x^2+13x-30=0

$$x ^ { 2 } + 13 x - 30 = 0$$

Whakaoti mō x

$$x=-15$$

$$x=2$$

Ngā Upane Whakamahi Tauwehe

Hei whakaoti i te whārite, whakatauwehea te x^{2}+13x-30 mā te whakamahi i te tātai x^{2}+\left(a+b\right)x+ab=\left(x+a\right)\left(x+b\right). Hei kimi a me b, whakaritea tētahi pūnaha kia whakaoti.

$$a+b=13 ab=-30$$

I te mea kua tōraro te ab, he tauaro ngā tohu o a me b. I te mea kua tōrunga te a+b, he nui ake te uara pū o te tau tōrunga i tō te tōraro. Whakarārangitia ngā tau tōpū takirua pērā katoa ka hoatu i te hua -30.

$$-1,30 -2,15 -3,10 -5,6$$

Tātaihia te tapeke mō ia takirua.

$$-1+30=29 -2+15=13 -3+10=7 -5+6=1$$

Ko te otinga te takirua ka hoatu i te tapeke 13.

$$a=-2 b=15$$

Me tuhi anō te kīanga whakatauwehe \left(x+a\right)\left(x+b\right) mā ngā uara i tātaihia.

$$\left(x-2\right)\left(x+15\right)$$

Hei kimi otinga whārite, me whakaoti te x-2=0 me te x+15=0.

$$x=2 x=-15$$

Ngā Upane Whakamahi Tauwehe Mā te Whakarōpū

Hei whakaoti i te whārite, whakatauwehea te taha mauī mā te whakarōpū. Tuatahi, me tuhi anō te taha mauī hei x^{2}+ax+bx-30. Hei kimi a me b, whakaritea tētahi pūnaha kia whakaoti.

$$a+b=13 ab=1\left(-30\right)=-30$$

I te mea kua tōraro te ab, he tauaro ngā tohu o a me b. I te mea kua tōrunga te a+b, he nui ake te uara pū o te tau tōrunga i tō te tōraro. Whakarārangitia ngā tau tōpū takirua pērā katoa ka hoatu i te hua -30.

$$-1,30 -2,15 -3,10 -5,6$$

Tātaihia te tapeke mō ia takirua.

$$-1+30=29 -2+15=13 -3+10=7 -5+6=1$$

Ko te otinga te takirua ka hoatu i te tapeke 13.

$$a=-2 b=15$$

Tuhia anō te x^{2}+13x-30 hei \left(x^{2}-2x\right)+\left(15x-30\right).

$$\left(x^{2}-2x\right)+\left(15x-30\right)$$

Tauwehea te x i te tuatahi me te 15 i te rōpū tuarua.

$$x\left(x-2\right)+15\left(x-2\right)$$

Whakatauwehea atu te kīanga pātahi x-2 mā te whakamahi i te āhuatanga tātai tohatoha.

$$\left(x-2\right)\left(x+15\right)$$

Hei kimi otinga whārite, me whakaoti te x-2=0 me te x+15=0.

$$x=2 x=-15$$

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

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.

$$x^{2}+13x-30=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi 1 mō a, 13 mō b, me -30 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{-13±\sqrt{13^{2}-4\left(-30\right)}}{2}$$

Pūrua 13.

$$x=\frac{-13±\sqrt{169-4\left(-30\right)}}{2}$$

Whakareatia -4 ki te -30.

$$x=\frac{-13±\sqrt{169+120}}{2}$$

Tāpiri 169 ki te 120.

$$x=\frac{-13±\sqrt{289}}{2}$$

Tuhia te pūtakerua o te 289.

$$x=\frac{-13±17}{2}$$

Nā, me whakaoti te whārite x=\frac{-13±17}{2} ina he tāpiri te ±. Tāpiri -13 ki te 17.

$$x=\frac{4}{2}$$

Whakawehe 4 ki te 2.

$$x=2$$

Nā, me whakaoti te whārite x=\frac{-13±17}{2} ina he tango te ±. Tango 17 mai i -13.

$$x=-\frac{30}{2}$$

Whakawehe -30 ki te 2.

$$x=-15$$

Kua oti te whārite te whakatau.

$$x=2 x=-15$$

Ngā Upane mō te Whakaoti i te Pūrua

Ko ngā whārite pūrua pēnei i tēnei nā ka taea te whakaoti mā te whakaoti i te pūrua. Hei whakaoti i te pūrua, ko te whārite me mātua tuhi ki te āhua x^{2}+bx=c.

$$x^{2}+13x-30=0$$

Me tāpiri 30 ki ngā taha e rua o te whārite.

$$x^{2}+13x-30-\left(-30\right)=-\left(-30\right)$$

Mā te tango i te -30 i a ia ake anō ka toe ko te 0.

$$x^{2}+13x=-\left(-30\right)$$

Tango -30 mai i 0.

$$x^{2}+13x=30$$

Whakawehea te 13, te tau whakarea o te kīanga tau x, ki te 2 kia riro ai te \frac{13}{2}. Nā, tāpiria te pūrua o te \frac{13}{2} ki ngā taha e rua o te whārite. Mā konei e pūrua tika tonu ai te taha mauī o te whārite.

$$x^{2}+13x+\left(\frac{13}{2}\right)^{2}=30+\left(\frac{13}{2}\right)^{2}$$

Pūruatia \frac{13}{2} mā te pūrua i te taurunga me te tauraro o te hautanga.

$$x^{2}+13x+\frac{169}{4}=30+\frac{169}{4}$$

Tāpiri 30 ki te \frac{169}{4}.

$$x^{2}+13x+\frac{169}{4}=\frac{289}{4}$$

Tauwehea x^{2}+13x+\frac{169}{4}. Ko te tikanga pūnoa, ina ko x^{2}+bx+c he pūrua tika pūrua tika pū, ka taea taua mea te tauwehea i ngā wā katoa hei \left(x+\frac{b}{2}\right)^{2}.

$$\left(x+\frac{13}{2}\right)^{2}=\frac{289}{4}$$

Tuhia te pūtakerua o ngā taha e rua o te whārite.

$$\sqrt{\left(x+\frac{13}{2}\right)^{2}}=\sqrt{\frac{289}{4}}$$

Whakarūnātia.

$$x+\frac{13}{2}=\frac{17}{2} x+\frac{13}{2}=-\frac{17}{2}$$

Me tango \frac{13}{2} mai i ngā taha e rua o te whārite.

$$x=2 x=-15$$