Whakaoti i te {l}{4x-2y=8}{2x+y=2}

$$\left\{ \begin{array} { l } { 4 x - 2 y = 8 } \\ { 2 x + y = 2 } \end{array} \right.$$

Whakaoti mō x, y

$$x = \frac{3}{2} = 1\frac{1}{2} = 1.5$$

$$y=-1$$

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.

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

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

$$4x-2y=8$$

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

$$4x=2y+8$$

Whakawehea ngā taha e rua ki te 4.

$$x=\frac{1}{4}\left(2y+8\right)$$

Whakareatia \frac{1}{4} ki te 8+2y.

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

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

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

Whakareatia 2 ki te \frac{y}{2}+2.

$$y+4+y=2$$

Tāpiri y ki te y.

$$2y+4=2$$

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

$$2y=-2$$

Whakawehea ngā taha e rua ki te 2.

$$y=-1$$

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

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

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

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

Tāpiri 2 ki te -\frac{1}{2}.

$$x=\frac{3}{2}$$

Kua oti te pūnaha te whakatau.

$$x=\frac{3}{2},y=-1$$

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.

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

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}4&-2\\2&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}8\\2\end{matrix}\right)$$

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

$$inverse(\left(\begin{matrix}4&-2\\2&1\end{matrix}\right))\left(\begin{matrix}4&-2\\2&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}4&-2\\2&1\end{matrix}\right))\left(\begin{matrix}8\\2\end{matrix}\right)$$

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

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}4&-2\\2&1\end{matrix}\right))\left(\begin{matrix}8\\2\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}4&-2\\2&1\end{matrix}\right))\left(\begin{matrix}8\\2\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{4-\left(-2\times 2\right)}&-\frac{-2}{4-\left(-2\times 2\right)}\\-\frac{2}{4-\left(-2\times 2\right)}&\frac{4}{4-\left(-2\times 2\right)}\end{matrix}\right)\left(\begin{matrix}8\\2\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{8}&\frac{1}{4}\\-\frac{1}{4}&\frac{1}{2}\end{matrix}\right)\left(\begin{matrix}8\\2\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{8}\times 8+\frac{1}{4}\times 2\\-\frac{1}{4}\times 8+\frac{1}{2}\times 2\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{3}{2}\\-1\end{matrix}\right)$$

Tangohia ngā huānga poukapa x me y.

$$x=\frac{3}{2},y=-1$$

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.

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

Kia ōrite ai a 4x 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 4.

$$2\times 4x+2\left(-2\right)y=2\times 8,4\times 2x+4y=4\times 2$$

Whakarūnātia.

$$8x-4y=16,8x+4y=8$$

Me tango 8x+4y=8 mai i 8x-4y=16 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$8x-8x-4y-4y=16-8$$

Tāpiri 8x ki te -8x. Ka whakakore atu ngā kupu 8x me -8x, ka toe he whārite me tētahi taurangi kotahi ka taea te whakaoti.

$$-4y-4y=16-8$$

Tāpiri -4y ki te -4y.

$$-8y=16-8$$

Tāpiri 16 ki te -8.

$$-8y=8$$

Whakawehea ngā taha e rua ki te -8.

$$y=-1$$

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

$$2x-1=2$$

Me tāpiri 1 ki ngā taha e rua o te whārite.

$$2x=3$$

Whakawehea ngā taha e rua ki te 2.

$$x=\frac{3}{2}$$

Kua oti te pūnaha te whakatau.

$$x=\frac{3}{2},y=-1$$