SECTION 6.2SOLVING EQUATIONS BYUSING SCALES
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BALANCING EQUATING WITH SCALES:
When there is an “equal” sign, it indicates that both sides ofthe equation are equal
If we add values only to one side, the scale will tip and not equal
To solve the equation weneed to isolate “x” bytaking out the samevalues from both sides
Subtract 4 from bothsides because there’s aplus 4 on the right
Divide both sides by 3because “x” ismultiplied by 3
So “X” is equal to 3.5
Rule: Whatever we do to isolate “x” on one side, we must do thesame operation to the other side
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EX: HOW MUCH DOES ONE STAR COST?
1
1
1
1
1
1
1
1
Ex: Record all your steps
1. Remove one starfrom sides
2. Subtract twocoins from sides
3. Divide each sideinto two groups
4. Now there’s only one staron the left side and twocoins on the right side
Therefore one star isequal to 2 coins
1
1
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The goal of this question is to find out how much little boxes oneyellow stick is equal to
PRACTICE: SOLVE THE FOLLOWING EQUATIONS FOR “X”
Add “x” toboth sides
Add 2 toboth sides
Divide each
side into 4 groups
Subtract “x”
from both sides
Add 3
Divide each side into 4 groups
Divide eachside by -1
Flip the colour on each side
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PRACTICE: SOLVE EACH EQUATION & VERIFY THE SOLUTION:
Subtract 10from bothsides
Multiplyby-2
Divideby 3
Add 4.5 toboth sides
Multiplyby 3
Divideby 4
There are 2 ways to do this question
Divideby-2
Add 3 toboth sides
Divideby -1
Expand theright side
Subtract 6from both sides
Divide bothsides by 2
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Ex: A taxi ride costs $5 for the base cost and then $0.45per minute. If a taxi ride costs $15.35, how long wasthe ride? Write an equation to solve the problem
Let the variable “C”represent the cost
Let the variable “T”represent thenumber of minutes
The ride was23 minutes long
Formula:
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PRACTICE: SOLVE THE FOLLOWING EQUATIONS FOR “X”
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HOMEWORK:
P281 # 7, 10, 14, 17, 19 , 20
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