Transcript Slide 1

Dividing Rational Numbers
1.
 12bc  28xy
2.
 81.5 0.3  5.4
2
3.
Note: For this problem, 2 × 3 is considered
different from 3 × 2
Dividing Rational Numbers
Since multiplication and division are inverse
operations, the rule for finding the sign of the
quotient of two numbers is similar to the rule
for finding the sign of a product of two
numbers.
Dividing Rational Numbers
Dividing Numbers with the Same Sign
The quotient of two numbers with the same sign is positive.
Examples:
 12   3  4
12  3  4
Dividing Rational Numbers
Dividing Numbers with Different Signs
The quotient of two numbers with different signs is negative.
Examples:
 12  4  3
12   4  3
Divide Integers
Find
Answer:
.
positive quotient
Divide Integers
Find
.
Divide.
Answer:
negative quotient
Divide Integers
Find each quotient.
a.
Answer: 20
b.
Answer: –15
Simplify Before Dividing
Simplify
Simplify the numerator first.
Multiply.
Answer:
different signs 
negative quotient
Simplify Before Dividing
Simplify
Answer: 3
Dividing Rational Numbers
The rules for dividing positive and negative
integers also apply to division with rational
numbers.
Divide Rational Numbers
Find
.
Estimate: – 108 ÷ 9 = – 12
Answer:
Use a calculator.
different signs 
negative quotient
Dividing Rational Numbers
Remember that to divide by any nonzero
number, multiply by the reciprocal of that
number.
Divide Rational Numbers
Find
.
–
No calculator!!
Multiply by
the reciprocal
of
Answer:
same signs  positive quotient
Divide Rational Numbers
Find each quotient.
a.
Answer: 15.3
b.
Answer:
Dividing Rational Numbers
 4
 5 .6
 56
Page 86 #18 – 36 even (10 problems – 10 points)
Divide Rational Numbers
Baseball The perimeter of a square baseball diamond
is 360 feet. Find the length of one side of the diamond.
To find the length of one side, divide the perimeter by the
number of sides.
same signs  positive quotient
Answer: The length of one side is 90 feet.
Divide Rational Numbers
The perimeter of a triangular building is 450 feet. Find
the length of each side.
Answer: 150 feet
You can use the Distributive Property to simplify
fractional expressions.
Simplify Algebraic Expressions
Simplify
The fraction bar
indicates division.
Multiply by
the reciprocal of 13.
Distributive Property.
Answer:
Simplify.
Do this one in your notes, PLEASE!!
Simplify Algebraic Expressions
Simplify
  51  34c   17
 
1
1







  51  17  34c  17 
1
  51  34c    17
 3   2c
Answer:
Evaluate Algebraic Expressions
Evaluate
if w = 2, x = –9.1 and y = 4.
Replace w with 2, x with –9.1
and y with 4.
Find the numerator and
denominator separately.
Answer:
Use a calculator.
different signs  negative quotient
Evaluate Algebraic Expressions
Evaluate
if s = 2.3, t = 5 and u = –4.
Answer: –14.375