x – 7 ≥ 0 x ≥ 7 x – 7 = 2x -x = 7 x = -7 nesplňuje podmínku x ≥ 7

x – 7 ≤ 0 x ≤ 7 -(x – 7) = 2x -x + 7 = 2x -3x = -7 x =

x =