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

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

Whakaoti mō y, x

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

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

Ngā Upane e Whakamahi ana i te Whakakapinga

Whakaarohia te whārite tuatahi. Tangohia te 3x mai i ngā taha e rua.

$$y-3x=7$$

Whakaarohia te whārite tuarua. Tangohia te x mai i ngā taha e rua.

$$y-x=4$$

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.

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

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

$$y-3x=7$$

Me tāpiri 3x ki ngā taha e rua o te whārite.

$$y=3x+7$$

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

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

Tāpiri 3x ki te -x.

$$2x+7=4$$

Me tango 7 mai i ngā taha e rua o te whārite.

$$2x=-3$$

Whakawehea ngā taha e rua ki te 2.

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

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

$$y=3\left(-\frac{3}{2}\right)+7$$

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

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

Tāpiri 7 ki te -\frac{9}{2}.

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

Kua oti te pūnaha te whakatau.

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

Ngā Upane e Whakamahi ana i Ngā Poukapa

Whakaarohia te whārite tuatahi. Tangohia te 3x mai i ngā taha e rua.

$$y-3x=7$$

Whakaarohia te whārite tuarua. Tangohia te x mai i ngā taha e rua.

$$y-x=4$$

Tuhia ngā whārite ki te tānga ngahuru ka whakamahi i ngā poukapa hei whakaoti i te pūnaha o ngā whārite.

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

Tuhia ngā whārite ki te tikanga tātai poukapa.

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

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

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

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

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

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

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

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.

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

Mahia ngā tātaitanga.

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

Whakareatia ngā poukapa.

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

Mahia ngā tātaitanga.

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

Tangohia ngā huānga poukapa y me x.

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

Ngā Upane e Whakamahi i te Tangohanga

Whakaarohia te whārite tuatahi. Tangohia te 3x mai i ngā taha e rua.

$$y-3x=7$$

Whakaarohia te whārite tuarua. Tangohia te x mai i ngā taha e rua.

$$y-x=4$$

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.

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

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

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

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.

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

Tāpiri -3x ki te x.

$$-2x=7-4$$

Tāpiri 7 ki te -4.

$$-2x=3$$

Whakawehea ngā taha e rua ki te -2.

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

Whakaurua te -\frac{3}{2} mō x ki y-x=4. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō y hāngai tonu.

$$y-\left(-\frac{3}{2}\right)=4$$

Whakareatia -1 ki te -\frac{3}{2}.

$$y+\frac{3}{2}=4$$

Me tango \frac{3}{2} mai i ngā taha e rua o te whārite.

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

Kua oti te pūnaha te whakatau.

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