Whakaoti i te =4b^2-8b+4-9

$$= 4 b ^ { 2 } - 8 b + 4 - 9$$

Tauwehe

$$\left(2b-5\right)\left(2b+1\right)$$

Ngā Upane Otinga

Whakarea ka paheko i ngā kīanga tau ōrite.

$$4b^{2}-8b-5$$

Whakatauwehea te kīanga mā te whakarōpū. Tuatahi, me tuhi anō te kīanga hei 4b^{2}+pb+qb-5. Hei kimi p me q, whakaritea tētahi pūnaha kia whakaoti.

$$p+q=-8 pq=4\left(-5\right)=-20$$

I te mea kua tōraro te pq, he tauaro ngā tohu o p me q. I te mea kua tōraro te p+q, he nui ake te uara pū o te tau tōraro i tō te tōrunga. Whakarārangitia ngā tau tōpū takirua pērā katoa ka hoatu i te hua -20.

$$1,-20 2,-10 4,-5$$

Tātaihia te tapeke mō ia takirua.

$$1-20=-19 2-10=-8 4-5=-1$$

Ko te otinga te takirua ka hoatu i te tapeke -8.

$$p=-10 q=2$$

Tuhia anō te 4b^{2}-8b-5 hei \left(4b^{2}-10b\right)+\left(2b-5\right).

$$\left(4b^{2}-10b\right)+\left(2b-5\right)$$

Whakatauwehea atu 2b i te 4b^{2}-10b.

$$2b\left(2b-5\right)+2b-5$$

Whakatauwehea atu te kīanga pātahi 2b-5 mā te whakamahi i te āhuatanga tātai tohatoha.

$$\left(2b-5\right)\left(2b+1\right)$$

Aromātai

$$\left(2b-5\right)\left(2b+1\right)$$

Ngā Upane Otinga

Tangohia te 9 i te 4, ka -5.

$$4b^{2}-8b-5$$