Câu 4 :
b, 4(x -1) + 3x - 5 =0
⇔ 4x - 4 +3x -5 = 0
⇔ 7x - 9 =0
⇔ 7x = 9
⇔ x = $\frac{9}{7}$
c, -1$\frac{1}{3}$x² +x = 0
⇔ -$\frac{4}{3}$x² + x = 0
⇔ x($\frac{-4}{3}$x + 1) = 0
⇒ \(\left[ \begin{array}{l}x=0\\x=\frac{-4}{3}x + 1=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{1}x=0\\x=\frac{3}{4}\end{array} \right.\)