Whakaoti i te 4200*0.2*(x-20)=385*0.0372*(400-x)

$$4200 \times 0.2 \times (x-20)=385 \times 0.0372 \times (400-x)$$

Whakaoti mō x

$$x = \frac{536400}{20341} = 26\frac{7534}{20341} \approx 26.370384937$$

Ngā Upane mō te Whakaoti Whārite Rārangi

Whakareatia te 4200 ki te 0.2, ka 840.

$$840\left(x-20\right)=385\times 0.0372\left(400-x\right)$$

Whakamahia te āhuatanga tohatoha hei whakarea te 840 ki te x-20.

$$840x-16800=385\times 0.0372\left(400-x\right)$$

Whakareatia te 385 ki te 0.0372, ka 14.322.

$$840x-16800=14.322\left(400-x\right)$$

Whakamahia te āhuatanga tohatoha hei whakarea te 14.322 ki te 400-x.

$$840x-16800=5728.8-14.322x$$

Me tāpiri te 14.322x ki ngā taha e rua.

$$840x-16800+14.322x=5728.8$$

Pahekotia te 840x me 14.322x, ka 854.322x.

$$854.322x-16800=5728.8$$

Me tāpiri te 16800 ki ngā taha e rua.

$$854.322x=5728.8+16800$$

Tāpirihia te 5728.8 ki te 16800, ka 22528.8.

$$854.322x=22528.8$$

Whakawehea ngā taha e rua ki te 854.322.

$$x=\frac{22528.8}{854.322}$$

Whakarohaina te \frac{22528.8}{854.322} mā te whakarea i te taurunga me te tauraro ki te 1000.

$$x=\frac{22528800}{854322}$$

Whakahekea te hautanga \frac{22528800}{854322} ki ōna wāhi pāpaku rawa mā te tango me te whakakore i te 42.

$$x=\frac{536400}{20341}$$