Whakaoti i te -3x^2+21=13

$$- 3 x ^ { 2 } + 21 = 13$$

Whakaoti mō x

$$x = \frac{2 \sqrt{6}}{3} \approx 1.632993162$$

$$x = -\frac{2 \sqrt{6}}{3} \approx -1.632993162$$

Ngā Upane mā te Kimi Pūtakerua

Tangohia te 21 mai i ngā taha e rua.

$$-3x^{2}=13-21$$

Tangohia te 21 i te 13, ka -8.

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

Whakawehea ngā taha e rua ki te -3.

$$x^{2}=\frac{-8}{-3}$$

Ka taea te hautanga \frac{-8}{-3} te whakamāmā ki te \frac{8}{3} mā te tango tahi i te tohu tōraro i te taurunga me te tauraro.

$$x^{2}=\frac{8}{3}$$

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

$$x=\frac{2\sqrt{6}}{3} x=-\frac{2\sqrt{6}}{3}$$

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

Tangohia te 13 mai i ngā taha e rua.

$$-3x^{2}+21-13=0$$

Tangohia te 13 i te 21, ka 8.

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

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi -3 mō a, 0 mō b, me 8 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-3\right)\times 8}}{2\left(-3\right)}$$

Pūrua 0.

$$x=\frac{0±\sqrt{-4\left(-3\right)\times 8}}{2\left(-3\right)}$$

Whakareatia -4 ki te -3.

$$x=\frac{0±\sqrt{12\times 8}}{2\left(-3\right)}$$

Whakareatia 12 ki te 8.

$$x=\frac{0±\sqrt{96}}{2\left(-3\right)}$$

Tuhia te pūtakerua o te 96.

$$x=\frac{0±4\sqrt{6}}{2\left(-3\right)}$$

Whakareatia 2 ki te -3.

$$x=\frac{0±4\sqrt{6}}{-6}$$

Nā, me whakaoti te whārite x=\frac{0±4\sqrt{6}}{-6} ina he tāpiri te ±.

$$x=-\frac{2\sqrt{6}}{3}$$

Nā, me whakaoti te whārite x=\frac{0±4\sqrt{6}}{-6} ina he tango te ±.

$$x=\frac{2\sqrt{6}}{3}$$

Kua oti te whārite te whakatau.

$$x=-\frac{2\sqrt{6}}{3} x=\frac{2\sqrt{6}}{3}$$