Whakaoti i te {c}{x+4y=12}{2x-y=6}

$$\left\{ \begin{array} { c } { x + 4 y = 12 } \\ { 2 x - y = 6 } \end{array} \right.$$

Whakaoti mō x, y

$$x=4$$

$$y=2$$

Ngā Upane e Whakamahi ana i te Whakakapinga

Hei whakaoti i ētahi whārite takirua mā te whakakapinga, me whakaoti tētahi whārite i te tuatahi mō tētahi o ngā taurangi. Ka whakakapi i te otinga mō taua taurangi ki tērā o ngā whārite.

$$x+4y=12,2x-y=6$$

Kōwhiria tētahi o ngā whārite ka whakaotia mō te x mā te wehe i te x i te taha mauī o te tohu ōrite.

$$x+4y=12$$

Me tango 4y mai i ngā taha e rua o te whārite.

$$x=-4y+12$$

Whakakapia te -4y+12 mō te x ki tērā atu whārite, 2x-y=6.

$$2\left(-4y+12\right)-y=6$$

Whakareatia 2 ki te -4y+12.

$$-8y+24-y=6$$

Tāpiri -8y ki te -y.

$$-9y+24=6$$

Me tango 24 mai i ngā taha e rua o te whārite.

$$-9y=-18$$

Whakawehea ngā taha e rua ki te -9.

$$y=2$$

Whakaurua te 2 mō y ki x=-4y+12. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$x=-4\times 2+12$$

Whakareatia -4 ki te 2.

$$x=-8+12$$

Tāpiri 12 ki te -8.

$$x=4$$

Kua oti te pūnaha te whakatau.

$$x=4,y=2$$

Ngā Upane e Whakamahi ana i Ngā Poukapa

Tuhia ngā whārite ki te tānga ngahuru ka whakamahi i ngā poukapa hei whakaoti i te pūnaha o ngā whārite.

$$x+4y=12,2x-y=6$$

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}1&4\\2&-1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}12\\6\end{matrix}\right)$$

Whakarea mauī i te whārite ki te poukapa kōaro o \left(\begin{matrix}1&4\\2&-1\end{matrix}\right).

$$inverse(\left(\begin{matrix}1&4\\2&-1\end{matrix}\right))\left(\begin{matrix}1&4\\2&-1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&4\\2&-1\end{matrix}\right))\left(\begin{matrix}12\\6\end{matrix}\right)$$

Ko te hua o tētahi poukapa me te kōaro ko te poukapa tuakiri.

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&4\\2&-1\end{matrix}\right))\left(\begin{matrix}12\\6\end{matrix}\right)$$

Whakareatia ngā poukapa kei te taha mauī o te tohu ōrite.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&4\\2&-1\end{matrix}\right))\left(\begin{matrix}12\\6\end{matrix}\right)$$

Mō te poukapa 2\times 2 \left(\begin{matrix}a&b\\c&d\end{matrix}\right), ko te \left(\begin{matrix}\frac{d}{ad-bc}&\frac{-b}{ad-bc}\\\frac{-c}{ad-bc}&\frac{a}{ad-bc}\end{matrix}\right) te poukapa kōaro, nō reira ka taea te tuhi anō te whārite poukapa hei rapanga whakarea poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{1}{-1-4\times 2}&-\frac{4}{-1-4\times 2}\\-\frac{2}{-1-4\times 2}&\frac{1}{-1-4\times 2}\end{matrix}\right)\left(\begin{matrix}12\\6\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{9}&\frac{4}{9}\\\frac{2}{9}&-\frac{1}{9}\end{matrix}\right)\left(\begin{matrix}12\\6\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{9}\times 12+\frac{4}{9}\times 6\\\frac{2}{9}\times 12-\frac{1}{9}\times 6\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}4\\2\end{matrix}\right)$$

Tangohia ngā huānga poukapa x me y.

$$x=4,y=2$$

Ngā Upane e Whakamahi i te Tangohanga

Hei whakaoti mā te tangohanga, ko ngā tau whakarea o tētahi o ngā taurangi me mātua ōrite i ngā whārite e rua kia whakakorehia ai te taurangi ina tangohia tētahi whārite mai i tētahi atu.

$$x+4y=12,2x-y=6$$

Kia ōrite ai a x me 2x, whakareatia ngā kīanga tau katoa kei ia taha o te whārite tuatahi ki te 2 me ngā kīanga tau katoa kei ia taha o te whārite tuarua ki te 1.

$$2x+2\times 4y=2\times 12,2x-y=6$$

Whakarūnātia.

$$2x+8y=24,2x-y=6$$

Me tango 2x-y=6 mai i 2x+8y=24 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$2x-2x+8y+y=24-6$$

Tāpiri 2x ki te -2x. Ka whakakore atu ngā kupu 2x me -2x, ka toe he whārite me tētahi taurangi kotahi ka taea te whakaoti.

$$8y+y=24-6$$

Tāpiri 8y ki te y.

$$9y=24-6$$

Tāpiri 24 ki te -6.

$$9y=18$$

Whakawehea ngā taha e rua ki te 9.

$$y=2$$

Whakaurua te 2 mō y ki 2x-y=6. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$2x-2=6$$

Me tāpiri 2 ki ngā taha e rua o te whārite.

$$2x=8$$

Whakawehea ngā taha e rua ki te 2.

$$x=4$$

Kua oti te pūnaha te whakatau.

$$x=4,y=2$$