Whakaoti i te m^2+2m=7

$$m ^ { 2 } + 2 m = 7$$

Whakaoti mō m

$$m=2\sqrt{2}-1\approx 1.828427125$$

$$m=-2\sqrt{2}-1\approx -3.828427125$$

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.

$$m^{2}+2m=7$$

Me tango 7 mai i ngā taha e rua o te whārite.

$$m^{2}+2m-7=7-7$$

Mā te tango i te 7 i a ia ake anō ka toe ko te 0.

$$m^{2}+2m-7=0$$

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

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

Pūrua 2.

$$m=\frac{-2±\sqrt{4-4\left(-7\right)}}{2}$$

Whakareatia -4 ki te -7.

$$m=\frac{-2±\sqrt{4+28}}{2}$$

Tāpiri 4 ki te 28.

$$m=\frac{-2±\sqrt{32}}{2}$$

Tuhia te pūtakerua o te 32.

$$m=\frac{-2±4\sqrt{2}}{2}$$

Nā, me whakaoti te whārite m=\frac{-2±4\sqrt{2}}{2} ina he tāpiri te ±. Tāpiri -2 ki te 4\sqrt{2}.

$$m=\frac{4\sqrt{2}-2}{2}$$

Whakawehe 4\sqrt{2}-2 ki te 2.

$$m=2\sqrt{2}-1$$

Nā, me whakaoti te whārite m=\frac{-2±4\sqrt{2}}{2} ina he tango te ±. Tango 4\sqrt{2} mai i -2.

$$m=\frac{-4\sqrt{2}-2}{2}$$

Whakawehe -2-4\sqrt{2} ki te 2.

$$m=-2\sqrt{2}-1$$

Kua oti te whārite te whakatau.

$$m=2\sqrt{2}-1 m=-2\sqrt{2}-1$$

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.

$$m^{2}+2m=7$$

Whakawehea te 2, te tau whakarea o te kīanga tau x, ki te 2 kia riro ai te 1. Nā, tāpiria te pūrua o te 1 ki ngā taha e rua o te whārite. Mā konei e pūrua tika tonu ai te taha mauī o te whārite.

$$m^{2}+2m+1^{2}=7+1^{2}$$

Pūrua 1.

$$m^{2}+2m+1=7+1$$

Tāpiri 7 ki te 1.

$$m^{2}+2m+1=8$$

Tauwehea m^{2}+2m+1. 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}.

$$\left(m+1\right)^{2}=8$$

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

$$\sqrt{\left(m+1\right)^{2}}=\sqrt{8}$$

Whakarūnātia.

$$m+1=2\sqrt{2} m+1=-2\sqrt{2}$$

Me tango 1 mai i ngā taha e rua o te whārite.

$$m=2\sqrt{2}-1 m=-2\sqrt{2}-1$$