Whakaoti i te {l}{x-y=3}{3x+y=8}

$$\left\{ \begin{array} { l } { x - y = 3 } \\ { 3 x + y = 8 } \end{array} \right.$$

Whakaoti mō x, y

$$x = \frac{11}{4} = 2\frac{3}{4} = 2.75$$

$$y=-\frac{1}{4}=-0.25$$

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.

$$x-y=3,3x+y=8$$

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

$$x-y=3$$

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

$$x=y+3$$

Whakakapia te y+3 mō te x ki tērā atu whārite, 3x+y=8.

$$3\left(y+3\right)+y=8$$

Whakareatia 3 ki te y+3.

$$3y+9+y=8$$

Tāpiri 3y ki te y.

$$4y+9=8$$

Me tango 9 mai i ngā taha e rua o te whārite.

$$4y=-1$$

Whakawehea ngā taha e rua ki te 4.

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

Whakaurua te -\frac{1}{4} mō y ki x=y+3. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$x=-\frac{1}{4}+3$$

Tāpiri 3 ki te -\frac{1}{4}.

$$x=\frac{11}{4}$$

Kua oti te pūnaha te whakatau.

$$x=\frac{11}{4},y=-\frac{1}{4}$$

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.

$$x-y=3,3x+y=8$$

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}1&-1\\3&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}3\\8\end{matrix}\right)$$

Whakarea mauī i te whārite ki te poukapa kōaro o \left(\begin{matrix}1&-1\\3&1\end{matrix}\right).

$$inverse(\left(\begin{matrix}1&-1\\3&1\end{matrix}\right))\left(\begin{matrix}1&-1\\3&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&-1\\3&1\end{matrix}\right))\left(\begin{matrix}3\\8\end{matrix}\right)$$

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

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&-1\\3&1\end{matrix}\right))\left(\begin{matrix}3\\8\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&-1\\3&1\end{matrix}\right))\left(\begin{matrix}3\\8\end{matrix}\right)$$

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.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{1-\left(-3\right)}&-\frac{-1}{1-\left(-3\right)}\\-\frac{3}{1-\left(-3\right)}&\frac{1}{1-\left(-3\right)}\end{matrix}\right)\left(\begin{matrix}3\\8\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{4}&\frac{1}{4}\\-\frac{3}{4}&\frac{1}{4}\end{matrix}\right)\left(\begin{matrix}3\\8\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{1}{4}\times 3+\frac{1}{4}\times 8\\-\frac{3}{4}\times 3+\frac{1}{4}\times 8\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{11}{4}\\-\frac{1}{4}\end{matrix}\right)$$

Tangohia ngā huānga poukapa x me y.

$$x=\frac{11}{4},y=-\frac{1}{4}$$

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.

$$x-y=3,3x+y=8$$

Kia ōrite ai a x me 3x, whakareatia ngā kīanga tau katoa kei ia taha o te whārite tuatahi ki te 3 me ngā kīanga tau katoa kei ia taha o te whārite tuarua ki te 1.

$$3x+3\left(-1\right)y=3\times 3,3x+y=8$$

Whakarūnātia.

$$3x-3y=9,3x+y=8$$

Me tango 3x+y=8 mai i 3x-3y=9 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$3x-3x-3y-y=9-8$$

Tāpiri 3x ki te -3x. Ka whakakore atu ngā kupu 3x me -3x, ka toe he whārite me tētahi taurangi kotahi ka taea te whakaoti.

$$-3y-y=9-8$$

Tāpiri -3y ki te -y.

$$-4y=9-8$$

Tāpiri 9 ki te -8.

$$-4y=1$$

Whakawehea ngā taha e rua ki te -4.

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

Whakaurua te -\frac{1}{4} mō y ki 3x+y=8. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$3x-\frac{1}{4}=8$$

Me tāpiri \frac{1}{4} ki ngā taha e rua o te whārite.

$$3x=\frac{33}{4}$$

Whakawehea ngā taha e rua ki te 3.

$$x=\frac{11}{4}$$

Kua oti te pūnaha te whakatau.

$$x=\frac{11}{4},y=-\frac{1}{4}$$