SAT SUBJECT TEST MATH LEVEL 1
TOPICS IN ARITHMETIC
CHAPTER 2
Basic Arithmetic
EXPONENTS AND ROOTS
In the expression bn, which is read “b to the nth,” “b to the nth power,” or “b raised to the nth power,” b is called the base and n is called the exponent. Almost all of the exponents that appear in questions on the Math 1 test are integers. Integer exponents are defined in the next KEY FACT.
Key Fact A10
For any number b and positive integer n:
• if b 0, then b0= 1
• b1= b
• if n > 1, then where b is a factor n times
•
For example,
Several rules govern the use of exponents in mathematics. The most important ones are listed in the next KEY FACT.
Key Fact A11
LAWS OF EXPONENTS
For any numbers b and c and integers m and n:
• bmbn = bm+n
•
• (bm)n = bmn
• bmcm = (bc)m
TIP
Memorize the laws of exponents. They come up quite often on the Math 1 test.
For example,
EXAMPLE 2: If 4m 4n= 410, what is the average (arithmetic mean) of m and n?
Since 4m 4n = 4m+n: