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Lesson 73 -- Factoring the Difference of Two Squares -- Probability Without Replacement. Factoring the Difference of Two Squares. Background: Remember when multiplying two binomials we use the FOIL method. Observe the following special case:.
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Lesson 73--Factoring the Difference of Two Squares--Probability Without Replacement
Factoring the Difference of Two Squares Background: Remember when multiplying two binomials we use the FOIL method. Observe the following special case: When we multiply two binomials that are the sum and difference of the same two numbers we have: - ab + ab - b2 = a2 - b2 = a2 In this lesson we are factoring (the inverse of multiplying) so… we reverse everything in the above example: Factor: a2 -b2
Factoring the Difference of Two Squares Example 73.1 Factor:
Factoring the Difference of Two Squares Example 73.2 Factor:
Factoring the Difference of Two Squares Example 73.3 Factor:
Factoring the Difference of Two Squares Example 73.4 Factor:
Probability Without Replacement Example 73.5 An urn contains 3 black marbles and 5 white marbles. A marble is drawn at random and replaced. Then a second marble is randomly drawn. (a) What is the probability that both marbles are black? (b) If the first marble is not replaced before the second marble is drawn, what is the probability that both marbles are black?
Probability Without Replacement Example 73.6 An urn contains 4 red marbles and 7 blue marbles. Two marbles are drawn at random. What is the probability that the first is red and the second is blue if the marbles are drawn (a) with replacement? (b) without replacement? 2 5