Transcript Solving Proportional Equations

Solving Proportional Equations
Thursday, March 31, 2016
We are learning to…solve
problems that involve proportional
reasoning.
When is using the Equivalent Ratios
Method not a good idea?
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Terri eats 13 grapes in 23 minutes. At this
rate how many grapes will she eat in 37
minutes?
Solve this proportional reasoning problem
using the Equivalent Ratios Method.
When might using the equivalent ratios
method not be the best way to find the
solution to a proportional relationship
problem?
Solving Proportional Equations
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Today we are going to use our equation solving skills
to solve proportional relationships.
When solving equations:
–
–
–
–
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To eliminate ADDITION we used: SUBTRACTION
To eliminate SUBTRACTION we used: ADDITION
To eliminate MULTIPLCATION we used: DIVISION
To eliminate DIVISION we will use: MULTIPLICAT`ION
The goal when solving any equation is to isolate the
variable.
How would you isolate the variable for the equation
1/ x
3
1/ x
3
1/ x
3
x
=
x
4
3
?
x
4
3
x
(3)  4 (3)
3
x  12
CHECK:
12
4
3
How would you isolate the variable
without creating a drawing?
y
 16
7
y
(7)  16(7)
7
y  112
CHECK!
Are these equivalent
fractions?
112
 16
7
 10  6 7 
 10  7   6  7 
 70  42
Use the Distributive Property
How would you isolate the variable
without creating a drawing?
x 6

4 8
x 6
(4)  (4)
4 8
x3
CHECK!
Are these equivalent
fractions?
3 6

4 8
Multiply by the Numerator:
 6 4  24
Divide by the Denominator:
24  8
How would you isolate the variable
without creating a drawing?
Multiply by the Numerator:
58  40
Divide by the Denominator:
40  9  ?
How many times does 9 go into 40
without going over?
4 whole times (36), with 4 left over
So…
4
4
9
8 g

9 5
8 g
(5)  (5)
9 5
4
g4
9