Whakaoti i te (4-x)(4-x)=9

$$(4-x)(4-x)=9$$

Whakaoti mō x

$$x=1$$

$$x=7$$

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

Whakareatia te 4-x ki te 4-x, ka \left(4-x\right)^{2}.

$$\left(4-x\right)^{2}=9$$

Whakamahia te ture huarua \left(a-b\right)^{2}=a^{2}-2ab+b^{2} hei whakaroha \left(4-x\right)^{2}.

$$16-8x+x^{2}=9$$

Tangohia te 9 mai i ngā taha e rua.

$$16-8x+x^{2}-9=0$$

Tangohia te 9 i te 16, ka 7.

$$7-8x+x^{2}=0$$

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.

$$x^{2}-8x+7=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi 1 mō a, -8 mō b, me 7 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{-\left(-8\right)±\sqrt{\left(-8\right)^{2}-4\times 7}}{2}$$

Pūrua -8.

$$x=\frac{-\left(-8\right)±\sqrt{64-4\times 7}}{2}$$

Whakareatia -4 ki te 7.

$$x=\frac{-\left(-8\right)±\sqrt{64-28}}{2}$$

Tāpiri 64 ki te -28.

$$x=\frac{-\left(-8\right)±\sqrt{36}}{2}$$

Tuhia te pūtakerua o te 36.

$$x=\frac{-\left(-8\right)±6}{2}$$

Ko te tauaro o -8 ko 8.

$$x=\frac{8±6}{2}$$

Nā, me whakaoti te whārite x=\frac{8±6}{2} ina he tāpiri te ±. Tāpiri 8 ki te 6.

$$x=\frac{14}{2}$$

Whakawehe 14 ki te 2.

$$x=7$$

Nā, me whakaoti te whārite x=\frac{8±6}{2} ina he tango te ±. Tango 6 mai i 8.

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

Whakawehe 2 ki te 2.

$$x=1$$

Kua oti te whārite te whakatau.

$$x=7 x=1$$

Ngā Upane mō te Whakaoti i te Pūrua

Whakareatia te 4-x ki te 4-x, ka \left(4-x\right)^{2}.

$$\left(4-x\right)^{2}=9$$

Whakamahia te ture huarua \left(a-b\right)^{2}=a^{2}-2ab+b^{2} hei whakaroha \left(4-x\right)^{2}.

$$16-8x+x^{2}=9$$

Tangohia te 16 mai i ngā taha e rua.

$$-8x+x^{2}=9-16$$

Tangohia te 16 i te 9, ka -7.

$$-8x+x^{2}=-7$$

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.

$$x^{2}-8x=-7$$

Whakawehea te -8, te tau whakarea o te kīanga tau x, ki te 2 kia riro ai te -4. Nā, tāpiria te pūrua o te -4 ki ngā taha e rua o te whārite. Mā konei e pūrua tika tonu ai te taha mauī o te whārite.

$$x^{2}-8x+\left(-4\right)^{2}=-7+\left(-4\right)^{2}$$

Pūrua -4.

$$x^{2}-8x+16=-7+16$$

Tāpiri -7 ki te 16.

$$x^{2}-8x+16=9$$

Tauwehea x^{2}-8x+16. 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}.

$$\left(x-4\right)^{2}=9$$

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

$$\sqrt{\left(x-4\right)^{2}}=\sqrt{9}$$

Whakarūnātia.

$$x-4=3 x-4=-3$$

Me tāpiri 4 ki ngā taha e rua o te whārite.

$$x=7 x=1$$