Negative Exponents

When a is a nonzero Real number and n and m are Whole numbers, then

a3 expands to a  a  a

an  am = an + m    The Product Rule: when multipling two numbers with the same base, add the exponents

an / am = an - m  The Quotient Rule: when dividing two numbers with the same base, subtract the exponent of the denominator (divisor) from the exponent of the numerator (dividend).

(a
n)m = anm        The Power Rule: when raising an expponetiated number to a power, multiply the exponent times the power.

(x + a)
2  expands to   (x + a)(x + a)   and simplifies to   x2 + 2ax + a2

(x  a)2   expands to   (x  a)(x  a)  and simplifies to   x2 – 2ax + a2

When squaring a binomial, the product will ALWAYS be a trinomial!

Conjugate binomials    Difference of Squares
   (x + a)(x  a)                  x
2  a2

A positive exponent means that we are multiplying by the base.
Ex: 23 = 2 • 2 • 2 = 8

A negative exponent means that we are dividing by the base.
Ex: 2–3 = 1/2 • 1/2 • 1/2 = 1/8 


To change the sign of the exponent, invert (flip) the base.
Ex: 2–3 = (1/2)3 = 1/8

When a base has a negative exponent, it needs to move to the other side of the fraction bar.
Ex: x-3 / y-2 = y2 / x3