Question

(x+1)(x+2)=(2-x)(x+2)

Answer 1

(𝑥+1)(𝑥+2)=(𝑥−2)(𝑥+2)

Đáp án:

𝑥²+3𝑥+2=𝑥²−4

Answer 2

(x+1)(x+2)=(2-x)(x+2)

(x+1)(x+2)-(2-x)(x+2)=0 

(x+2)(x+1-2+x)=0 

x+2=0 hoặc 2x-1=0 

x=-2 hoặc x=1/2

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Answer 3

 \(\left(x+1\right)\left(x+2\right)=\left(2-x\right)\left(x+2\right)\)

\(\Leftrightarrow x^2+2x+x+2=4-x^2\)

\(\Leftrightarrow2x^2+3x-2=0\)

\(\Leftrightarrow2x^2+4x-x-2=0\)

\(\Leftrightarrow2x\left(x+2\right)-\left(x+2\right)=0\)

\(\Leftrightarrow\left(x+2\right)\left(2x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+2=0\\2x-1=0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=\dfrac{1}{2}\end{matrix}\right.\)

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