Variables and Like Terms

1
Variables and Like Terms

• Section 2-2-1

2
Variables

• A variable holds a place for a number.
• Any letter can be used.
• x6
• 3-7y
• 2t-3s6r2

3
Expressions

• Does not contain and equal sign
• A combination of variables, numbers and
  operations
• An EQUATION is made of expressions

4
Equations

• An equation contains an equal sign
• It is made of expressions
• 2x-6 5x2 has an expression on each side of the
  equation.

5
Term

• A term is part of an expression that is added or
  subtracted.
• In 3x2 4x 3 3x2, 4x and 3 are the terms.
• Three parts
• Variable
• Exponent -The power to which the variable is
  raised
• Coefficient The number in front of the variable.

6
Terms

• Identify the coefficient, exponent and variable
  for the following terms.
• 7x3
• -8x2
• 2x
• -3x2
• 7x
• x5

7
Like Terms

• For terms to be like terms everything must
  match except the coefficients.
• Which of the following are like terms?

8
Like terms

• Like terms can be added or subtracted.
• 3x 5x
• 8y2s 3y2s
• What about m3-x3-7m3