Whakaoti i te {l}{x+4y=1}{2x+y=-5}

$$\left\{ \begin{array} { l } { x + 4 y = 1 } \\ { 2 x + y = - 5 } \end{array} \right.$$

Whakaoti mō x, y

$$x=-3$$

$$y=1$$

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.

$$x+4y=1,2x+y=-5$$

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

$$x+4y=1$$

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

$$x=-4y+1$$

Whakakapia te -4y+1 mō te x ki tērā atu whārite, 2x+y=-5.

$$2\left(-4y+1\right)+y=-5$$

Whakareatia 2 ki te -4y+1.

$$-8y+2+y=-5$$

Tāpiri -8y ki te y.

$$-7y+2=-5$$

Me tango 2 mai i ngā taha e rua o te whārite.

$$-7y=-7$$

Whakawehea ngā taha e rua ki te -7.

$$y=1$$

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

$$x=-4+1$$

Tāpiri 1 ki te -4.

$$x=-3$$

Kua oti te pūnaha te whakatau.

$$x=-3,y=1$$

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.

$$x+4y=1,2x+y=-5$$

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}1&4\\2&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}1\\-5\end{matrix}\right)$$

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

$$inverse(\left(\begin{matrix}1&4\\2&1\end{matrix}\right))\left(\begin{matrix}1&4\\2&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&4\\2&1\end{matrix}\right))\left(\begin{matrix}1\\-5\end{matrix}\right)$$

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

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&4\\2&1\end{matrix}\right))\left(\begin{matrix}1\\-5\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&4\\2&1\end{matrix}\right))\left(\begin{matrix}1\\-5\end{matrix}\right)$$

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.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{1-4\times 2}&-\frac{4}{1-4\times 2}\\-\frac{2}{1-4\times 2}&\frac{1}{1-4\times 2}\end{matrix}\right)\left(\begin{matrix}1\\-5\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{1}{7}&\frac{4}{7}\\\frac{2}{7}&-\frac{1}{7}\end{matrix}\right)\left(\begin{matrix}1\\-5\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{1}{7}+\frac{4}{7}\left(-5\right)\\\frac{2}{7}-\frac{1}{7}\left(-5\right)\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-3\\1\end{matrix}\right)$$

Tangohia ngā huānga poukapa x me y.

$$x=-3,y=1$$

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.

$$x+4y=1,2x+y=-5$$

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.

$$2x+2\times 4y=2,2x+y=-5$$

Whakarūnātia.

$$2x+8y=2,2x+y=-5$$

Me tango 2x+y=-5 mai i 2x+8y=2 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$2x-2x+8y-y=2+5$$

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.

$$8y-y=2+5$$

Tāpiri 8y ki te -y.

$$7y=2+5$$

Tāpiri 2 ki te 5.

$$7y=7$$

Whakawehea ngā taha e rua ki te 7.

$$y=1$$

Whakaurua te 1 mō y ki 2x+y=-5. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$2x+1=-5$$

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

$$2x=-6$$

Whakawehea ngā taha e rua ki te 2.

$$x=-3$$

Kua oti te pūnaha te whakatau.

$$x=-3,y=1$$