`|3-2x|=3x-7`
⇔\(\left[ \begin{array}{l}3-2x=3x-7( khi 3-2x≥0)\\-3+2x=3x-7( khi 3-2x<0)\end{array} \right.\)
⇔\(\left[ \begin{array}{l}-3x-2x=-7-3( khi 2x≤3)\\2x-3x=-7+3( khi 2x>3)\end{array} \right.\)
⇔\(\left[ \begin{array}{l}5x=10( khi x≤3/2)\\x=4( khi x>3/2)\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=2( loại)\\x=4( nhận)\end{array} \right.\)
Vậy `S={4}`
