Whakaoti i te {l}{4x-5y=18}{3x-2y=10}

$$\left. \begin{array} { l } { 4 x - 5 y = 18 } \\ { 3 x - 2 y = 10 } \end{array} \right.$$

Whakaoti mō x, y

$$x=2$$

$$y=-2$$

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.

$$4x-5y=18,3x-2y=10$$

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

$$4x-5y=18$$

Me tāpiri 5y ki ngā taha e rua o te whārite.

$$4x=5y+18$$

Whakawehea ngā taha e rua ki te 4.

$$x=\frac{1}{4}\left(5y+18\right)$$

Whakareatia \frac{1}{4} ki te 5y+18.

$$x=\frac{5}{4}y+\frac{9}{2}$$

Whakakapia te \frac{5y}{4}+\frac{9}{2} mō te x ki tērā atu whārite, 3x-2y=10.

$$3\left(\frac{5}{4}y+\frac{9}{2}\right)-2y=10$$

Whakareatia 3 ki te \frac{5y}{4}+\frac{9}{2}.

$$\frac{15}{4}y+\frac{27}{2}-2y=10$$

Tāpiri \frac{15y}{4} ki te -2y.

$$\frac{7}{4}y+\frac{27}{2}=10$$

Me tango \frac{27}{2} mai i ngā taha e rua o te whārite.

$$\frac{7}{4}y=-\frac{7}{2}$$

Whakawehea ngā taha e rua o te whārite ki te \frac{7}{4}, he ōrite ki te whakarea i ngā taha e rua ki te tau huripoki o te hautanga.

$$y=-2$$

Whakaurua te -2 mō y ki x=\frac{5}{4}y+\frac{9}{2}. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$x=\frac{5}{4}\left(-2\right)+\frac{9}{2}$$

Whakareatia \frac{5}{4} ki te -2.

$$x=\frac{-5+9}{2}$$

Tāpiri \frac{9}{2} ki te -\frac{5}{2} mā te kimi i te tauraro pātahi me te tāpiri i ngā taurunga. Ka whakaiti i te hautanga ki ngā kīanga tau iti rawa e taea ana.

$$x=2$$

Kua oti te pūnaha te whakatau.

$$x=2,y=-2$$

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.

$$4x-5y=18,3x-2y=10$$

Tuhia ngā whārite ki te tikanga tātai poukapa.

$$\left(\begin{matrix}4&-5\\3&-2\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}18\\10\end{matrix}\right)$$

Whakarea mauī i te whārite ki te poukapa kōaro o \left(\begin{matrix}4&-5\\3&-2\end{matrix}\right).

$$inverse(\left(\begin{matrix}4&-5\\3&-2\end{matrix}\right))\left(\begin{matrix}4&-5\\3&-2\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}4&-5\\3&-2\end{matrix}\right))\left(\begin{matrix}18\\10\end{matrix}\right)$$

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

$$\left(\begin{matrix}1&0\\0&1\end{matrix}\right)\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}4&-5\\3&-2\end{matrix}\right))\left(\begin{matrix}18\\10\end{matrix}\right)$$

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

$$\left(\begin{matrix}x\\y\end{matrix}\right)=inverse(\left(\begin{matrix}4&-5\\3&-2\end{matrix}\right))\left(\begin{matrix}18\\10\end{matrix}\right)$$

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.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{2}{4\left(-2\right)-\left(-5\times 3\right)}&-\frac{-5}{4\left(-2\right)-\left(-5\times 3\right)}\\-\frac{3}{4\left(-2\right)-\left(-5\times 3\right)}&\frac{4}{4\left(-2\right)-\left(-5\times 3\right)}\end{matrix}\right)\left(\begin{matrix}18\\10\end{matrix}\right)$$

Mahia ngā tātaitanga.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{2}{7}&\frac{5}{7}\\-\frac{3}{7}&\frac{4}{7}\end{matrix}\right)\left(\begin{matrix}18\\10\end{matrix}\right)$$

Whakareatia ngā poukapa.

$$\left(\begin{matrix}x\\y\end{matrix}\right)=\left(\begin{matrix}-\frac{2}{7}\times 18+\frac{5}{7}\times 10\\-\frac{3}{7}\times 18+\frac{4}{7}\times 10\end{matrix}\right)$$

Mahia ngā tātaitanga.

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

Tangohia ngā huānga poukapa x me y.

$$x=2,y=-2$$

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.

$$4x-5y=18,3x-2y=10$$

Kia ōrite ai a 4x 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 4.

$$3\times 4x+3\left(-5\right)y=3\times 18,4\times 3x+4\left(-2\right)y=4\times 10$$

Whakarūnātia.

$$12x-15y=54,12x-8y=40$$

Me tango 12x-8y=40 mai i 12x-15y=54 mā te tango i ngā kīanga tau ōrite i ia taha o te tohu ōrite.

$$12x-12x-15y+8y=54-40$$

Tāpiri 12x ki te -12x. Ka whakakore atu ngā kupu 12x me -12x, ka toe he whārite me tētahi taurangi kotahi ka taea te whakaoti.

$$-15y+8y=54-40$$

Tāpiri -15y ki te 8y.

$$-7y=54-40$$

Tāpiri 54 ki te -40.

$$-7y=14$$

Whakawehea ngā taha e rua ki te -7.

$$y=-2$$

Whakaurua te -2 mō y ki 3x-2y=10. I te mea kotahi anake te taurangi kei te whārite i puta, ka taea e koe te whakaoti mō x hāngai tonu.

$$3x-2\left(-2\right)=10$$

Whakareatia -2 ki te -2.

$$3x+4=10$$

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

$$3x=6$$

Whakawehea ngā taha e rua ki te 3.

$$x=2$$

Kua oti te pūnaha te whakatau.

$$x=2,y=-2$$