`a, 5 - (6 - x) = 4(3 - 2x)`
`⇔ 5 - 6 + x = 12 - 8x`
`⇔ 9x = 13`
`⇔ x = 13/9`
`b, (3x + 2)^2 + (3x - 2)^2 = 5x + 8`
`⇔ 9x^2 + 12x + 4 + 9x^2 - 12x + 4 = 5x + 8`
`⇔ 18x^2 - 5x = 0`
`⇔ x(18x - 5) = 0`
`⇔` \(\left[ \begin{array}{l}x=0\\18x-5=0\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}x=0\\x=\dfrac{5}{18}\end{array} \right.\)
`c, (2x + 5)(x - 4) = (x - 5)(4 - x)`
`⇔ (2x + 5)(x - 4) - (x - 5)(4 - x) = 0`
`⇔ (2x + 5)(x - 4) + (x - 5)(x - 4) = 0`
`⇔ (2x + 5 + x - 5)(x - 4) = 0`
`⇔ 3x(x - 4) = 0`
`⇔` \(\left[ \begin{array}{l}3x=0\\x-4=0\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}x=0\\x=4\end{array} \right.\)
`d, \frac{14}{3x-12} - \frac{2+x}{x-4} = \frac{3}{8-2x} - 5/6` `(x \ne 4)`
`⇔ \frac{14}{3(x-4)} - \frac{2+x}{x-4} = \frac{3}{-2(x-4)} - 5/6`
`⇔ \frac{-28}{-6(x-4)} - \frac{-6(2+x)}{-6(x-4)} = \frac{9}{-6(x-4)} - \frac{-5(x-4)}{-6(x-4)}`
`⇒ -28 - [-6(2 + x)] = 9 - [-5(x - 4)]`
`⇔ -28 + 12 + 6x = 9 + 5x - 20`
`⇔ x = 5(TM)`
