Download Lecture Section 4.1 and 4.2

The least common multiple, or LCM, of two
natural numbers is the smallest number that is
a multiple of both numbers.
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Section 4.1
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Method 2: To find the LCM of a set of numbers using prime factorizations.
a) Find the prime factorization of each number.
b) Create a product, using each prime factor the greatest number of times
that it occurs in any one factorization.
Use a FACTOR
TREE!
Section 4.1
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Homework:
Problems 9, 11, 19, 21, 29, 33, 37, 39, 41, 45. Copy the problem first. Determine the answer using
methods 1 or 2 and shown in the lecture slides. If you can find the LCM another way, GREAT!, but
you must still show some work or justification.
Section 4.1
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Steps to follow:
To add when denominators are different:
a) Find the least common multiple of the
denominators. That number is the least common
denominator, LCD.
b) Convert each fraction to the LCD.
c) Add the numerators, keeping the same
denominator.
d) Simplify, if possible.
Section 4.1
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Let p = the number of pounds of tea Alyse bought.
Alyse bought 1/3 lb of orange pekoe
tea and 1/2 lb of English cinnamon tea.
How many pounds of tea did she buy?
Use the 4 step process to solve.
1 1
p 
3 2
2 3
p 
6 6
5
p  lb
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Alyse bought
5
lb of tea.
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Homework:
Problems 19, 33, 35. Copy the problem first.
Show all of your work in a top down manner.
Problems 37, 39, 41, 43, 45, 47, 49 Solve
using the 4 step process. Make sure you
show all of your work when solving the
equations.
Section 4.1
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