Exponents and Powers

1
Exponents and Powers

• An expression like 23 is called a power
• 23 2 ? 2 ? 2 8
• This expression is read as two to the third
  power or two cubed
• The repeated factor is the base
• The exponent indicates how many times the base is
  used as a factor
• A power with an exponent of 2 such as 32 can be
  read as three to the second power or three
  squared
• Variables can also be raised to a power
• For example, x6 is x to the sixth power, or x x
  x x x x
• Evaluate a power by replacing the variable with
  its value and calculating the answer
• Evaluate x4 for x 3
• Evaluate x4 for x -3
• Did you get the same answer? Why or why not?

base ? 23 ? exponent
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Grouping symbols

• Grouping symbols enclose parts of an expression
  that represent a single number
• Parentheses ( )
• Brackets
• Braces
• Absolute value symbols also act as grouping
  symbols
• A fraction bar is another grouping symbol
• The numerator and denominator are separate
  expressions
• Grouping symbols affect the result of power
  expressions
• For example
• -22 -4, while (-2)2 4
• 1 23 9, while (1 2)3 27