Variables: Plus and Minus

Back to “Basic Algebra” Page

Add x-terms to x-terms and y-terms to y-terms. Do not mix terms.

  • x + x =
    x + x = 2x
  • 2x + 2x =
    2x + 2x = 4x
  • 3x + 3x =
    3x + 3x = 6x
  • 4x + 5x =
    4x + 5x = 9x
  • 3x - 2x =
    3x - 2x = x
  • 5x - 3x =
    5x - 3x = 2x
  • 2x - 3x =
    2x - 3x = -x
  • 4x - 7x =
    4x - 7x = -3x
  • x + x + y + y =
    x + x + y + y =
    2x + 2y
  • 2x + x + 2y + y =
    2x + x + 2y + y =
    3x + 3y
  • 2x + 3x + 2y + 5y =
    2x + 3x + 2y + 5y =
    5x + 7y
  • 5x + 3x + 8y + 5y =
    5x + 3x + 8y + 5y =
    8x + 13y
  • 2x + y + x + 3y =
    2x + y + x + 3y =
    3x + 4y
  • 2x + y - x + 3y =
    2x + y - x + 3y =
    x + 4y
  • 5x + 3y - 2x - 2y =
    5x + 3y - 2x - 2y =
    3x + y
  • (5x + 3y) - 2x - 2y =
    (5x + 3y) - 2x - 2y =
    3x + y
  • 2x + y - x - 3y =
    2x + y - x - 3y =
    x - 2y
  • 2x + y - (x - 3y) =
    2x + y - (x - 3y) =
    x + 4y

Notice that in the last pair of cards, the parentheses change the answer because a -1 is distributed into the parentheses, changing the –3y to a +3y.