In the first semester, you learned how to multiply monomials. Here is a quick review, as the rules listed are important to understand the rest of the lesson.
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Multiplying Monomials
Rule
Symbols
Examples
Product of Powers
To multiply two powers that have the same base, add the exponents.
am ∙ an = am+n
a4∙ a9 = a13
Power of a Power
To find the power of a power, multiply the exponents.
(am)n = am∙n
(a3)4 = a12
Power of a Product
To find the power of a product, find the power of each factor and multiply.
(ab)n = anbn
(2a3)4 = 16a12
Another Way to Look at It
Group coefficients and common bases
Multiplying — add exponents
Power to a power — multiply exponents
Product to a power — take each to the power
Example 1: Finding a Product
Simplify each expression.
(3z5)(-z8)
= (3 · -1)(z5 · z8) Group
(–z8 = -1z8 by the multiplicative identity)
= -3z13 Multiply constants and add exponents
(-4xy3)(-2x5y5)
= (-4 · -2)(x · x5)(y3 · y5) Group
= 8x6y8 Multiply and add exponents
= (-2)4 (x5)4 (y-1)4 Product to a power – take each to the power
= 16 x5∙4 y-1∙4 Power to a power – multiply exponents
= 16x20y-4 Simplify = 16x20/ y4 Simplify (you cannot have negative exponents in your final answer)
Example 3: Simplify Expressions
Simplify . Use order of operations and begin with the inside parenthesis.