Whakaoti i te -x^2-6x+3.5=0

$$- { x }^{ 2 } -6x+3.5=0$$

Whakaoti mō x

$$x=\frac{5\sqrt{2}}{2}-3\approx 0.535533906$$

$$x=-\frac{5\sqrt{2}}{2}-3\approx -6.535533906$$

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.

$$-x^{2}-6x+3.5=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi -1 mō a, -6 mō b, me 3.5 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{-\left(-6\right)±\sqrt{\left(-6\right)^{2}-4\left(-1\right)\times 3.5}}{2\left(-1\right)}$$

Pūrua -6.

$$x=\frac{-\left(-6\right)±\sqrt{36-4\left(-1\right)\times 3.5}}{2\left(-1\right)}$$

Whakareatia -4 ki te -1.

$$x=\frac{-\left(-6\right)±\sqrt{36+4\times 3.5}}{2\left(-1\right)}$$

Whakareatia 4 ki te 3.5.

$$x=\frac{-\left(-6\right)±\sqrt{36+14}}{2\left(-1\right)}$$

Tāpiri 36 ki te 14.

$$x=\frac{-\left(-6\right)±\sqrt{50}}{2\left(-1\right)}$$

Tuhia te pūtakerua o te 50.

$$x=\frac{-\left(-6\right)±5\sqrt{2}}{2\left(-1\right)}$$

Ko te tauaro o -6 ko 6.

$$x=\frac{6±5\sqrt{2}}{2\left(-1\right)}$$

Whakareatia 2 ki te -1.

$$x=\frac{6±5\sqrt{2}}{-2}$$

Nā, me whakaoti te whārite x=\frac{6±5\sqrt{2}}{-2} ina he tāpiri te ±. Tāpiri 6 ki te 5\sqrt{2}.

$$x=\frac{5\sqrt{2}+6}{-2}$$

Whakawehe 6+5\sqrt{2} ki te -2.

$$x=-\frac{5\sqrt{2}}{2}-3$$

Nā, me whakaoti te whārite x=\frac{6±5\sqrt{2}}{-2} ina he tango te ±. Tango 5\sqrt{2} mai i 6.

$$x=\frac{6-5\sqrt{2}}{-2}$$

Whakawehe 6-5\sqrt{2} ki te -2.

$$x=\frac{5\sqrt{2}}{2}-3$$

Kua oti te whārite te whakatau.

$$x=-\frac{5\sqrt{2}}{2}-3 x=\frac{5\sqrt{2}}{2}-3$$

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.

$$-x^{2}-6x+3.5=0$$

Me tango 3.5 mai i ngā taha e rua o te whārite.

$$-x^{2}-6x+3.5-3.5=-3.5$$

Mā te tango i te 3.5 i a ia ake anō ka toe ko te 0.

$$-x^{2}-6x=-3.5$$

Whakawehea ngā taha e rua ki te -1.

$$\frac{-x^{2}-6x}{-1}=-\frac{3.5}{-1}$$

Mā te whakawehe ki te -1 ka wetekia te whakareanga ki te -1.

$$x^{2}+\left(-\frac{6}{-1}\right)x=-\frac{3.5}{-1}$$

Whakawehe -6 ki te -1.

$$x^{2}+6x=-\frac{3.5}{-1}$$

Whakawehe -3.5 ki te -1.

$$x^{2}+6x=3.5$$

Whakawehea te 6, te tau whakarea o te kīanga tau x, ki te 2 kia riro ai te 3. Nā, tāpiria te pūrua o te 3 ki ngā taha e rua o te whārite. Mā konei e pūrua tika tonu ai te taha mauī o te whārite.

$$x^{2}+6x+3^{2}=3.5+3^{2}$$

Pūrua 3.

$$x^{2}+6x+9=3.5+9$$

Tāpiri 3.5 ki te 9.

$$x^{2}+6x+9=12.5$$

Tauwehea x^{2}+6x+9. 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}.

$$\left(x+3\right)^{2}=12.5$$

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

$$\sqrt{\left(x+3\right)^{2}}=\sqrt{12.5}$$

Whakarūnātia.

$$x+3=\frac{5\sqrt{2}}{2} x+3=-\frac{5\sqrt{2}}{2}$$

Me tango 3 mai i ngā taha e rua o te whārite.

$$x=\frac{5\sqrt{2}}{2}-3 x=-\frac{5\sqrt{2}}{2}-3$$