Whakaoti i te {l}{2x+y=8}{x-2y=-1}

$$\left. \begin{array} { l } { 2 x + y = 8 } \\ { x - 2 y = - 1 } \end{array} \right.$$

Whakaoti mō x, y

$$x=3$$

$$y=2$$

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.

$$2x+y=8,x-2y=-1$$

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

$$2x+y=8$$

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

$$2x=-y+8$$

Whakawehea ngā taha e rua ki te 2.

$$x=\frac{1}{2}\left(-y+8\right)$$

Whakareatia \frac{1}{2} ki te -y+8.

$$x=-\frac{1}{2}y+4$$

Whakakapia te -\frac{y}{2}+4 mō te x ki tērā atu whārite, x-2y=-1.

$$-\frac{1}{2}y+4-2y=-1$$

Tāpiri -\frac{y}{2} ki te -2y.

$$-\frac{5}{2}y+4=-1$$

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

$$-\frac{5}{2}y=-5$$

Whakawehea ngā taha e rua o te whārite ki te -\frac{5}{2}, he ōrite ki te whakarea i ngā taha e rua ki te tau huripoki o te hautanga.

$$y=2$$

Whakaurua te 2 mō y ki x=-\frac{1}{2}y+4. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$x=-\frac{1}{2}\times 2+4$$

Whakareatia -\frac{1}{2} ki te 2.

$$x=-1+4$$

Tāpiri 4 ki te -1.

$$x=3$$

Kua oti te pūnaha te whakatau.

$$x=3,y=2$$

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.

$$2x+y=8,x-2y=-1$$

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}2&1\\1&-2\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}8\\-1\end{matrix}\right)$$

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

$$inverse(\left(\begin{matrix}2&1\\1&-2\end{matrix}\right))\left(\begin{matrix}2&1\\1&-2\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}2&1\\1&-2\end{matrix}\right))\left(\begin{matrix}8\\-1\end{matrix}\right)$$

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

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}2&1\\1&-2\end{matrix}\right))\left(\begin{matrix}8\\-1\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}2&1\\1&-2\end{matrix}\right))\left(\begin{matrix}8\\-1\end{matrix}\right)$$

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.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{2}{2\left(-2\right)-1}&-\frac{1}{2\left(-2\right)-1}\\-\frac{1}{2\left(-2\right)-1}&\frac{2}{2\left(-2\right)-1}\end{matrix}\right)\left(\begin{matrix}8\\-1\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{2}{5}&\frac{1}{5}\\\frac{1}{5}&-\frac{2}{5}\end{matrix}\right)\left(\begin{matrix}8\\-1\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{2}{5}\times 8+\frac{1}{5}\left(-1\right)\\\frac{1}{5}\times 8-\frac{2}{5}\left(-1\right)\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}3\\2\end{matrix}\right)$$

Tangohia ngā huānga poukapa x me y.

$$x=3,y=2$$

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.

$$2x+y=8,x-2y=-1$$

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

$$2x+y=8,2x+2\left(-2\right)y=2\left(-1\right)$$

Whakarūnātia.

$$2x+y=8,2x-4y=-2$$

Me tango 2x-4y=-2 mai i 2x+y=8 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$2x-2x+y+4y=8+2$$

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.

$$y+4y=8+2$$

Tāpiri y ki te 4y.

$$5y=8+2$$

Tāpiri 8 ki te 2.

$$5y=10$$

Whakawehea ngā taha e rua ki te 5.

$$y=2$$

Whakaurua te 2 mō y ki x-2y=-1. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$x-2\times 2=-1$$

Whakareatia -2 ki te 2.

$$x-4=-1$$

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

$$x=3$$

Kua oti te pūnaha te whakatau.

$$x=3,y=2$$