Whakaoti i te 3x^2+5x+2=8

$$3 { x }^{ 2 } +5x+2 = 8$$

Whakaoti mō x

$$x=\frac{\sqrt{97}-5}{6}\approx 0.808142967$$

$$x=\frac{-\sqrt{97}-5}{6}\approx -2.474809634$$

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.

$$3x^{2}+5x+2=8$$

Me tango 8 mai i ngā taha e rua o te whārite.

$$3x^{2}+5x+2-8=8-8$$

Mā te tango i te 8 i a ia ake anō ka toe ko te 0.

$$3x^{2}+5x+2-8=0$$

Tango 8 mai i 2.

$$3x^{2}+5x-6=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi 3 mō a, 5 mō b, me -6 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{-5±\sqrt{5^{2}-4\times 3\left(-6\right)}}{2\times 3}$$

Pūrua 5.

$$x=\frac{-5±\sqrt{25-4\times 3\left(-6\right)}}{2\times 3}$$

Whakareatia -4 ki te 3.

$$x=\frac{-5±\sqrt{25-12\left(-6\right)}}{2\times 3}$$

Whakareatia -12 ki te -6.

$$x=\frac{-5±\sqrt{25+72}}{2\times 3}$$

Tāpiri 25 ki te 72.

$$x=\frac{-5±\sqrt{97}}{2\times 3}$$

Whakareatia 2 ki te 3.

$$x=\frac{-5±\sqrt{97}}{6}$$

Nā, me whakaoti te whārite x=\frac{-5±\sqrt{97}}{6} ina he tāpiri te ±. Tāpiri -5 ki te \sqrt{97}.

$$x=\frac{\sqrt{97}-5}{6}$$

Nā, me whakaoti te whārite x=\frac{-5±\sqrt{97}}{6} ina he tango te ±. Tango \sqrt{97} mai i -5.

$$x=\frac{-\sqrt{97}-5}{6}$$

Kua oti te whārite te whakatau.

$$x=\frac{\sqrt{97}-5}{6} x=\frac{-\sqrt{97}-5}{6}$$

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.

$$3x^{2}+5x+2=8$$

Me tango 2 mai i ngā taha e rua o te whārite.

$$3x^{2}+5x+2-2=8-2$$

Mā te tango i te 2 i a ia ake anō ka toe ko te 0.

$$3x^{2}+5x=8-2$$

Tango 2 mai i 8.

$$3x^{2}+5x=6$$

Whakawehea ngā taha e rua ki te 3.

$$\frac{3x^{2}+5x}{3}=\frac{6}{3}$$

Mā te whakawehe ki te 3 ka wetekia te whakareanga ki te 3.

$$x^{2}+\frac{5}{3}x=\frac{6}{3}$$

Whakawehe 6 ki te 3.

$$x^{2}+\frac{5}{3}x=2$$

Whakawehea te \frac{5}{3}, te tau whakarea o te kīanga tau x, ki te 2 kia riro ai te \frac{5}{6}. Nā, tāpiria te pūrua o te \frac{5}{6} ki ngā taha e rua o te whārite. Mā konei e pūrua tika tonu ai te taha mauī o te whārite.

$$x^{2}+\frac{5}{3}x+\left(\frac{5}{6}\right)^{2}=2+\left(\frac{5}{6}\right)^{2}$$

Pūruatia \frac{5}{6} mā te pūrua i te taurunga me te tauraro o te hautanga.

$$x^{2}+\frac{5}{3}x+\frac{25}{36}=2+\frac{25}{36}$$

Tāpiri 2 ki te \frac{25}{36}.

$$x^{2}+\frac{5}{3}x+\frac{25}{36}=\frac{97}{36}$$

Tauwehea x^{2}+\frac{5}{3}x+\frac{25}{36}. 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}.

$$\left(x+\frac{5}{6}\right)^{2}=\frac{97}{36}$$

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

$$\sqrt{\left(x+\frac{5}{6}\right)^{2}}=\sqrt{\frac{97}{36}}$$

Whakarūnātia.

$$x+\frac{5}{6}=\frac{\sqrt{97}}{6} x+\frac{5}{6}=-\frac{\sqrt{97}}{6}$$

Me tango \frac{5}{6} mai i ngā taha e rua o te whārite.

$$x=\frac{\sqrt{97}-5}{6} x=\frac{-\sqrt{97}-5}{6}$$