Đáp án: cho pt ^2x-(m-1)x+2m-6=0 tìm m để phương trình trên có 2 nghiệm x1,x2 thỏa mãn x1/x2 + x2/x1 = 5/2 - Áp dụng hệ thức Vi-ét, ta có x_1+x_2=(m-1/1)=m-1 x_1x_2=(2m-6/1)=2m-6 (x_1/x_2)+(x_2/x_1)=5/2 <=>(x_1^2+x_2^2/x_1x_2)=5/2 <=>((x_1+x_2)^2-2x_1x_2/x_1x_2)=5/2 <=>((m-1)^2-2(2m-6)/2m-6)=(m^2-6m+13/2m-6)=5/2 <=>2m^2-12m+26=10m-30 <=>2m^2-22m+56=0 <=>[ begin(matrix) m=4 m=7 end(matrix)

Áp dụng hệ thức Vi-ét, ta có x_1+x_2=(m-1/1)=m-1 x_1x_2=(2m-6/1)=2m-6 (x_1/x_2)+(x_2/x_1)=5/2 <=>(x_1^2+x_2^2/x_1x_2)=5/2 <=>((x_1+x_2)^2-2x_1x_2/x_1x_2)=5/2 <=>((m-1)^2-2(2m-6)/2m-6)=(m^2-6m+13/2m-6)=5/2 <=>2m^2-12m+26=10m-30 <=>2m^2-22m+56=0 <=>[ begin(matrix) m=4 m=7 end(matrix)

haihoangdohai11

6 tháng trước

cho pt ^2x-(m-1)x+2m-6=0 tìm m để phương trình trên có 2 nghiệm x1,x2 thỏa mãn x1/x2 + x2/x1 = 5/2

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nnn3004

6 tháng trước

Áp dụng hệ thức Vi-ét, ta có:

\begin{cases} x_1+x_2=\frac{m-1}{1}=m-1\\ x_1.x_2=\frac{2m-6}{1}=2m-6 \end{cases}

`\frac{x_1}{x_2}+\frac{x_2}{x_1}=5/2`

`<=>\frac{x_1^2+x_2^2}{x_1.x_2}=5/2`

`<=>\frac{(x_1+x_2)^2-2x_1.x_2}{x_1.x_2}=5/2`

`<=>\frac{(m-1)^2-2(2m-6)}{2m-6}=\frac{m^2-6m+13}{2m-6}=5/2`

`<=>2m^2-12m+26=10m-30`

`<=>2m^2-22m+56=0`

`<=>`$\left[\begin{matrix} m=4\\ m=7\end{matrix}\right.$

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cho pt ^2x-(m-1)x+2m-6=0 tìm m để phương trình trên có 2 nghiệm x1,x2 thỏa mãn x1/x2 + x2/x1 = 5/2

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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.

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cho pt ^2x-(m-1)x+2m-6=0 tìm m để phương trình trên có 2 nghiệm x1,x2 thỏa mãn x1/x2 + x2/x1 = 5/2

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.