Whakaoti i te {l}{x-y=4}{3x-y=7}

$$\left.\begin{array} { l } { x - y = 4 } \\ { 3 x - y = 7 } \end{array} \right\}$$

Whakaoti mō x, y

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

$$y = -\frac{5}{2} = -2\frac{1}{2} = -2.5$$

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.

$$x-y=4,3x-y=7$$

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

$$x-y=4$$

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

$$x=y+4$$

Whakakapia te y+4 mō te x ki tērā atu whārite, 3x-y=7.

$$3\left(y+4\right)-y=7$$

Whakareatia 3 ki te y+4.

$$3y+12-y=7$$

Tāpiri 3y ki te -y.

$$2y+12=7$$

Me tango 12 mai i ngā taha e rua o te whārite.

$$2y=-5$$

Whakawehea ngā taha e rua ki te 2.

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

Whakaurua te -\frac{5}{2} mō y ki x=y+4. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$x=-\frac{5}{2}+4$$

Tāpiri 4 ki te -\frac{5}{2}.

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

Kua oti te pūnaha te whakatau.

$$x=\frac{3}{2},y=-\frac{5}{2}$$

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.

$$x-y=4,3x-y=7$$

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}1&-1\\3&-1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}4\\7\end{matrix}\right)$$

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

$$inverse(\left(\begin{matrix}1&-1\\3&-1\end{matrix}\right))\left(\begin{matrix}1&-1\\3&-1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&-1\\3&-1\end{matrix}\right))\left(\begin{matrix}4\\7\end{matrix}\right)$$

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

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&-1\\3&-1\end{matrix}\right))\left(\begin{matrix}4\\7\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}1&-1\\3&-1\end{matrix}\right))\left(\begin{matrix}4\\7\end{matrix}\right)$$

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.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{1}{-1-\left(-3\right)}&-\frac{-1}{-1-\left(-3\right)}\\-\frac{3}{-1-\left(-3\right)}&\frac{1}{-1-\left(-3\right)}\end{matrix}\right)\left(\begin{matrix}4\\7\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{1}{2}&\frac{1}{2}\\-\frac{3}{2}&\frac{1}{2}\end{matrix}\right)\left(\begin{matrix}4\\7\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{1}{2}\times 4+\frac{1}{2}\times 7\\-\frac{3}{2}\times 4+\frac{1}{2}\times 7\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}\frac{3}{2}\\-\frac{5}{2}\end{matrix}\right)$$

Tangohia ngā huānga poukapa x me y.

$$x=\frac{3}{2},y=-\frac{5}{2}$$

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.

$$x-y=4,3x-y=7$$

Me tango 3x-y=7 mai i x-y=4 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$x-3x-y+y=4-7$$

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

$$x-3x=4-7$$

Tāpiri x ki te -3x.

$$-2x=4-7$$

Tāpiri 4 ki te -7.

$$-2x=-3$$

Whakawehea ngā taha e rua ki te -2.

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

Whakaurua te \frac{3}{2} mō x ki 3x-y=7. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō y hāngai tonu.

$$3\times \frac{3}{2}-y=7$$

Whakareatia 3 ki te \frac{3}{2}.

$$\frac{9}{2}-y=7$$

Me tango \frac{9}{2} mai i ngā taha e rua o te whārite.

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

Whakawehea ngā taha e rua ki te -1.

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

Kua oti te pūnaha te whakatau.

$$x=\frac{3}{2},y=-\frac{5}{2}$$