Whakaoti i te (3x-7)^2-(3x+1)(3x-1)

$$( 3 x - 7 ) ^ { 2 } - ( 3 x + 1 ) ( 3 x - 1 )$$

Aromātai

$$50-42x$$

Ngā Upane Otinga

Whakamahia te ture huarua \left(a-b\right)^{2}=a^{2}-2ab+b^{2} hei whakaroha \left(3x-7\right)^{2}.

$$9x^{2}-42x+49-\left(3x+1\right)\left(3x-1\right)$$

Whakaarohia te \left(3x+1\right)\left(3x-1\right). Ka taea te whakareanga te panoni ki te rerekētanga o ngā pūrua mā te ture: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Pūrua 1.

$$9x^{2}-42x+49-\left(\left(3x\right)^{2}-1\right)$$

Whakarohaina te \left(3x\right)^{2}.

$$9x^{2}-42x+49-\left(3^{2}x^{2}-1\right)$$

Tātaihia te 3 mā te pū o 2, kia riro ko 9.

$$9x^{2}-42x+49-\left(9x^{2}-1\right)$$

Hei kimi i te tauaro o 9x^{2}-1, kimihia te tauaro o ia taurangi.

$$9x^{2}-42x+49-9x^{2}+1$$

Pahekotia te 9x^{2} me -9x^{2}, ka 0.

$$-42x+49+1$$

Tāpirihia te 49 ki te 1, ka 50.

$$-42x+50$$

Whakaroha

$$50-42x$$

Ngā Upane Otinga

Whakamahia te ture huarua \left(a-b\right)^{2}=a^{2}-2ab+b^{2} hei whakaroha \left(3x-7\right)^{2}.

$$9x^{2}-42x+49-\left(3x+1\right)\left(3x-1\right)$$

Whakaarohia te \left(3x+1\right)\left(3x-1\right). Ka taea te whakareanga te panoni ki te rerekētanga o ngā pūrua mā te ture: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Pūrua 1.

$$9x^{2}-42x+49-\left(\left(3x\right)^{2}-1\right)$$

Whakarohaina te \left(3x\right)^{2}.

$$9x^{2}-42x+49-\left(3^{2}x^{2}-1\right)$$

Tātaihia te 3 mā te pū o 2, kia riro ko 9.

$$9x^{2}-42x+49-\left(9x^{2}-1\right)$$

Hei kimi i te tauaro o 9x^{2}-1, kimihia te tauaro o ia taurangi.

$$9x^{2}-42x+49-9x^{2}+1$$

Pahekotia te 9x^{2} me -9x^{2}, ka 0.

$$-42x+49+1$$

Tāpirihia te 49 ki te 1, ka 50.

$$-42x+50$$