a)
[tex]8 + 6x - 5 - 2x=4x+12-9x\\\\4x+3 = -5x+12 \ \ \ |+5x\\\\4x+5x = 12-3\\\\9x = 9 \ \ /:9\\\\\boxed{x = 1}[/tex]
[tex]Spr.\\\\L = 8+6\cdot1 - 5 - 2\cdot1 = 8+6-5-2 = 7\\\\P = 4\cdot1 + 12 - 9\cdot1 = 4+12-9 = 7\\\\L = P[/tex]
b)
[tex]-4-5x+x+6 = 7-2x+9-4x\\\\-4x+2 = -6x+16 \ \ \ |+6x\\\\-4x+6x = 16-2\\\\2x = 14 \ \ /:2\\\\\boxed{x = 7}[/tex]
[tex]Spr.\\\\L = -4-5\cdot7+7+6 = -4-35+13 = -26\\\\P = 7-2\cdot7+9-4\cdot7 = 7-14+9-28 = -26\\\\L = P[/tex]
