Đáp án: giải phương trình x^2-x-4=2canx-1 (1-x) - x^2-x-4=2√(x-1)(1-x) ⇔x^2-x-4=2(1-x)x-1 ⇔(x^2-x-4)^2=4(1-x)^2(x-1) ⇔(x^2-x-4)^2=4x-4-8x^2+8x+4x^3-4x^2 ⇔(x^2-x-4)^2=12x-4-12x^2+4x^3 ⇔(x^2-x-4)^2-12x+4+12x^2-4x^3=0 ⇔x^4-6x^3+5x^2-4x+20=0 ⇔(x-2)(x-5)(x^2+x+2)=0 ⇔[ (l)x-2=0x-5=0(ktm) x^2+x+2=0(ktm) ⇔x=2 (Vậy pt có nghiệm S = (2))

x^2-x-4=2√(x-1)(1-x) ⇔x^2-x-4=2(1-x)x-1 ⇔(x^2-x-4)^2=4(1-x)^2(x-1) ⇔(x^2-x-4)^2=4x-4-8x^2+8x+4x^3-4x^2 ⇔(x^2-x-4)^2=12x-4-12x^2+4x^3 ⇔(x^2-x-4)^2-12x+4+12x^2-4x^3=0 ⇔x^4-6x^3+5x^2-4x+20=0 ⇔(x-2)(x-5)(x^2+x+2)=0 ⇔[ (l)x-2=0x-5=0(ktm) x^2+x+2=0(ktm) ⇔x=2 (Vậy pt có nghiệm S = (2))

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6 tháng trước

giải phương trình: x^2-x-4=2canx-1 (1-x)

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baonhivu1234

6 tháng trước

$x^2-x-4=2\sqrt{x-1}\left(1-x\right)$

$⇔x^2-x-4=2\left(1-x\right)x-1$

$⇔\left(x^2-x-4\right)^2=4\left(1-x\right)^2\left(x-1\right)$

$⇔\left(x^2-x-4\right)^2=4x-4-8x^2+8x+4x^3-4x^2$

$⇔\left(x^2-x-4\right)^2=12x-4-12x^2+4x^3$

$⇔\left(x^2-x-4\right)^2-12x+4+12x^2-4x^3=0$

$⇔x^4-6x^3+5x^2-4x+20=0$

$⇔\left(x-2\right)\left(x-5\right)\left(x^2+x+2\right)=0$

$⇔\left[ \begin{array}{l}x-2=0\\x-5=0(ktm)\quad \\x^2+x+2=0(ktm)\end{array} \right.$

$⇔x=2$

$\text{Vậy pt có nghiệm S = {2}}$

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giải phương trình: x^2-x-4=2canx-1 (1-x)

1 câu trả lời

Viết một đoạn văn hoàn chỉnh về lý do học tiếng Anh bằng cách đưa ra các manh mối ( ko chép mạng nhá)

việt nam dành độc lập vào năm nào

Choose the best answer.I think you should buy _____ pack of mineral water instead. And you can also buy _____ snacks such as potato crisps, 3 kilos of mandarins, 2 kilos of apples, 3 bunches of bananas, ______ cookies and soft candies.

Choose the best answer.We should decorate our living room with _____ orange banner. We also need ________ ribbons, balloons, party hats and costume.

Choose the best answer.I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.

Đề thi - đề kiểm tra Xem thêm

Choose the best answer.
I think you should buy ___ pack of mineral water instead. And you can also buy _ snacks such as potato crisps, 3 kilos of mandarins, 2 kilos of apples, 3 bunches of bananas, ____ cookies and soft candies.

Choose the best answer.
We should decorate our living room with _ orange banner. We also need ____ ribbons, balloons, party hats and costume.

Choose the best answer.
I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.