Question

     giải hệ phương trình phương  pháp thế 

Answer 1

d, \(\left\{{}\begin{matrix}y=2-\left(1-\sqrt{3}\right)x\\3x-\left(\sqrt{3}-1\right)\left[2-\left(1-\sqrt{3}\right)x\right]=1\left(2\right)\end{matrix}\right.\)

\(\left(2\right)\Rightarrow3x-2\left(\sqrt{3}-1\right)-\left(\sqrt{3}-1\right)^2x=1\)

\(\Leftrightarrow3x-2\sqrt{3}+2-\left(4-2\sqrt{3}\right)x=1\Leftrightarrow3x-2\sqrt{3}+2-4x+2\sqrt{3}x=1\)

\(\Leftrightarrow x\left(-1+2\sqrt{3}\right)=-1+2\sqrt{3}\Leftrightarrow x=1\)

\(\Rightarrow y=2-\left(1-\sqrt{3}\right)=1+\sqrt{3}\)