At regne med X'er

x + x = 2x 2x + 3x = 5x                       5x + 2x = 2 . 2x = 4x 2 . x = 2x 3 . 4x = 12x                       4 . 2x = Parenteser: 2(x + 2) = 2x + 4 2(2x + 3) = 4x + 12 -2(x + 2) = -2x - 4 -2(x - 2) = -2x + 4                       -2(-x + 2) =                       - (x - 2) =                          (x - 2) =

HUSK: