5A

1B

3C

4D

\(#TyHM\)

C

1 Unless there is a sudden change in public opinion, he will win the next election

a: \(S=\dfrac{4\cdot6}{2}=12\left(cm^2\right)\)

b: Độ dài hai đường chéo là 8;6

Cạnh là 5cm

\(\left\{{}\begin{matrix}\left(x+2\right)^2+\left(y-1\right)^2=x^2+y^2+7\left(1\right)\\\left(x+1\right)\left(y+2\right)=xy+5\left(2\right)\end{matrix}\right.\)

\(\left(2\right)\Leftrightarrow xy+2x+y+2=xy+5\Leftrightarrow2x+y+2=5\)

\(\Leftrightarrow y=3-2x\left(3\right)\)

\(\left(3\right)\left(1\right)\Rightarrow\left(x+2\right)^2+\left(2-2x\right)^2=x^2+\left(3-2x\right)^2+7\Rightarrow x=y=1\)

\(\left\{{}\begin{matrix}\dfrac{1}{x}+\dfrac{1}{y}=\dfrac{3}{4}\\\dfrac{1}{6x}+\dfrac{1}{5y}=\dfrac{2}{15}\end{matrix}\right.\)\(\left(x,y\ne0\right)\) \(đặt\left\{{}\begin{matrix}\dfrac{1}{x}=a\\\dfrac{1}{y}=b\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}a+b=\dfrac{3}{4}\\\dfrac{1}{6}a+\dfrac{1}{5}b=\dfrac{2}{15}\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}a=\dfrac{1}{2}\\b=\dfrac{1}{4}\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x=2\\y=4\end{matrix}\right.\)\(\left(tm\right)\)

https://coccoc.com/search/math#query=3(1-4x).(x-1)%2B4.(3x-2).(x%2B2)%2Bx2+%3D52++T%C3%ACm+x+

(3-12x)(x-1)+(12x-8)(x+2)+x²=52

3(x-1)-12x(x-1)+12x(x+2)-8(x+2)+x²=52

3x-3-12x²+12+12x²+24x-8x-16+x²=52

(3x+24x-8x)+(12-3-16)+(12x²-12x²+x²)=52

19x-7+x²=52

x(19-x)=52+7=59

mà 59 là số ng tố nên x rỗng

Vậy x E \(\theta\)

đang thi mik ko giúp đc, xin lỗi nha

Bh bạn thi xong vậy ạ 

Lỗi rùi, cập nhật lại nha

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