Whakaoti i te (40*28)-(1/2*20.5*28)=

$$(40 \times 28)-( \frac{ 1 }{ 2 } \times 20.5 \times 28)=$$

Aromātai

$$833$$

Ngā Upane Otinga

Whakareatia te 40 ki te 28, ka 1120.

$$1120-\frac{1}{2}\times 20.5\times 28$$

Me tahuri ki tau ā-ira 20.5 ki te hautau \frac{205}{10}. Whakahekea te hautanga \frac{205}{10} ki ōna wāhi pāpaku rawa mā te tango me te whakakore i te 5.

$$1120-\frac{1}{2}\times \frac{41}{2}\times 28$$

Me whakarea te \frac{1}{2} ki te \frac{41}{2} mā te whakarea taurunga ki te taurunga me te tauraro ki te tauraro.

$$1120-\frac{1\times 41}{2\times 2}\times 28$$

Mahia ngā whakarea i roto i te hautanga \frac{1\times 41}{2\times 2}.

$$1120-\frac{41}{4}\times 28$$

Tuhia te \frac{41}{4}\times 28 hei hautanga kotahi.

$$1120-\frac{41\times 28}{4}$$

Whakareatia te 41 ki te 28, ka 1148.

$$1120-\frac{1148}{4}$$

Whakawehea te 1148 ki te 4, kia riro ko 287.

$$1120-287$$

Tangohia te 287 i te 1120, ka 833.

$$833$$

Tauwehe

$$17\times 7^{2}$$