Whakaoti i te {l}{20+20*x/100=25}{25-25*y/100=20}

$$\left. \begin{array} { l } { 20 + 20 \times \frac { x } { 100 } = 25 } \\ { 25 - 25 \times \frac { y } { 100 } = 20 } \end{array} \right.$$

Whakaoti mō x, y

$$x=25$$

$$y=20$$

Ngā Upane Otinga

Whakaarohia te whārite tuatahi. Whakareatia ngā taha e rua o te whārite ki te 100.

$$2000+20x=2500$$

Tangohia te 2000 mai i ngā taha e rua.

$$20x=2500-2000$$

Tangohia te 2000 i te 2500, ka 500.

$$20x=500$$

Whakawehea ngā taha e rua ki te 20.

$$x=\frac{500}{20}$$

Whakawehea te 500 ki te 20, kia riro ko 25.

$$x=25$$

Whakaarohia te whārite tuarua. Whakareatia ngā taha e rua o te whārite ki te 100.

$$2500-25y=2000$$

Tangohia te 2500 mai i ngā taha e rua.

$$-25y=2000-2500$$

Tangohia te 2500 i te 2000, ka -500.

$$-25y=-500$$

Whakawehea ngā taha e rua ki te -25.

$$y=\frac{-500}{-25}$$

Whakawehea te -500 ki te -25, kia riro ko 20.

$$y=20$$

Kua oti te pūnaha te whakatau.

$$x=25 y=20$$