Đáp án+Giải thích các bước giải:
b)
`(x-(1)/(2))((9)/(4)-x^2)=0`
⇔\(\left[ \begin{array}{l}x-\frac{1}{2}=0\\\frac{9}{4}-x^2=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{1}{2}\\-x^2=-\frac{9}{4}\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{1}{2}\\x^2=\frac{9}{4}\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{1}{2}\\x^2=(\frac{3}{2})^2\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{1}{2}\\x=±\frac{3}{2}\end{array} \right.\)
Vậy S={`1/2`,±`3/2`}
