Whakaoti i te 5x*x=90

$$5x \times x=90$$

Whakaoti mō x

$$x=3\sqrt{2}\approx 4.242640687$$

$$x=-3\sqrt{2}\approx -4.242640687$$

Ngā Upane mā te Kimi Pūtakerua

Whakareatia te x ki te x, ka x^{2}.

$$5x^{2}=90$$

Whakawehea ngā taha e rua ki te 5.

$$x^{2}=\frac{90}{5}$$

Whakawehea te 90 ki te 5, kia riro ko 18.

$$x^{2}=18$$

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

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

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

Whakareatia te x ki te x, ka x^{2}.

$$5x^{2}=90$$

Tangohia te 90 mai i ngā taha e rua.

$$5x^{2}-90=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi 5 mō a, 0 mō b, me -90 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 5\left(-90\right)}}{2\times 5}$$

Pūrua 0.

$$x=\frac{0±\sqrt{-4\times 5\left(-90\right)}}{2\times 5}$$

Whakareatia -4 ki te 5.

$$x=\frac{0±\sqrt{-20\left(-90\right)}}{2\times 5}$$

Whakareatia -20 ki te -90.

$$x=\frac{0±\sqrt{1800}}{2\times 5}$$

Tuhia te pūtakerua o te 1800.

$$x=\frac{0±30\sqrt{2}}{2\times 5}$$

Whakareatia 2 ki te 5.

$$x=\frac{0±30\sqrt{2}}{10}$$

Nā, me whakaoti te whārite x=\frac{0±30\sqrt{2}}{10} ina he tāpiri te ±.

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

Nā, me whakaoti te whārite x=\frac{0±30\sqrt{2}}{10} ina he tango te ±.

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

Kua oti te whārite te whakatau.

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