Đáp án:
Giải thích các bước giải:
$y= -2x - x +3\\= -3x - 3\\\\\text{ta có BBT :}\\\begin{array}{c|cc} \text{$x$}&\text{$-\infty$}&\text{}&\text{}\\\hline \text{$y$}&+\infty\text{}&\text{}&\text{}&\text{}&\text{}&\text{}&\\&\text{}&\text{$\searrow$}&\text{}&\text{}\\&\text{$$}&\text{}&\text{}-\infty& \end{array}\\\text{Vậy : }\\(+)x = 0 \\\Rightarrow y = 3 \quad A(0 ; 3)\\(+)x = 1\\\Rightarrow y = 0 \quad B(1 ; 0)$
