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`a)` `2(x - 3) = -3(x -1) + 7`
`⇔` `2x - 6 = -3x + 3 + 7`
`⇔` `2x - 6 = -3x + 10`
`⇔` `2x - 6 + 3x - 10 = 0`
`⇔` `5x - 16 = 0`
`⇔` `5x = 16`
`⇔` `x = \frac{16}{5}`
`S = {\frac{16}{5}}`
`b)` `(x^2 -1)(x - 2)(x - 3) = 0`
`⇔` `(x - 1)(x + 1)(x - 2)(x - 3) = 0`
`⇔` \(\left[ \begin{array}{l}x - 1 = 0\\x + 1 = 0\\x - 2 = 0\\x - 3 = 0\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x = 1\\x = -1\\x = 2\\x = 3\end{array} \right.\)
`S = {-1; 1; 2; 3}`
`c)` `|5x - 3| = x + 7`; ĐKXĐ: `x \ge - 7`
`->` \(\left[ \begin{array}{l}5x - 3 = x +7\\5x - 3 =-(x + 7)\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}5x - 3 - x - 7 = 0\\5x + x = - 7 + 3\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}4x - 10 = 0\\6x = -4\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}4x = 10 \\x = \dfrac{-2}{3}\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x = \dfrac{5}{2}\\x= \dfrac{-2}{3}\end{array} \right.\)
`S = {\frac{5}{2}; \frac{-2}{3}}`
