` a) ` ` (x - 1)(2 - x) = 0 `
` <=> ` \(\left[ \begin{array}{l}x-1=0\\2-x=0\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x=1\\x=2\end{array} \right.\)
` b) ` ` (-x + 3)(-7 + x) = 0 `
` <=> ` \(\left[ \begin{array}{l}-x+3=0\\-7+x=0\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x=3\\x=7\end{array} \right.\)
` c) ` ` (x + 9)(x^2 - 25) = 0 `
` <=> ` \(\left[ \begin{array}{l}x+9=0\\x^2-25=0\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x=-9\\x^2=25\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x=-9\\x=5\\x=-5\end{array} \right.\)
` d) ` ` (2x - 5)-(x - 8) = 0 `
` <=> 2x - 5 - x + 8 = 0 `
` <=> 2x - x - 5 + 8 = 0 `
` <=> x + 3 = 0 `
` <=> x = -3 `
` e) ` ` (4x - 5)-(x + 1) = 0 `
` <=> 4x - 5 - x - 1 = 0 `
` <=> 4x - x - 5 - 1 = 0 `
` <=> 3x - 6 = 0 `
` <=> 3x = 6 `
` <=> x = 2 `
