Video and Examples
In this lesson you will continue using the bags and marbles model to help you in solving equations. This time, however, you will record each step with an algebraic equation and a verbal explanation. 
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Example 1 One bag plus 9 marbles weighs the same as 4 bags and 3 marbles. Find the number of marbles in each bag. 
According to the model and the algebraic equations, . However, it is important to check it by evaluating the original equation by subsituting 2 wherever we see an m.
Example 2 Two bags plus 10 marbles weighs the same as 5 bags and 1 marble. Find the number of marbles in each bag. 
Model  Algebraic equations  Write the equation and check the solution... 
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Example 3 One bag plus 8 marbles weighs the same as 5 bags. Find the number of marbles in each bag. 
Model  Algebraic equations  Write the equation and check the solution... 
[show answer] 
Example 4 Three bags plus 2 marbles weighs the same as 1 bag plus 10 marbles. Find the number of marbles in each bag. 
Model  Algebraic equations  Write the equation and check the solution... 
[show answer] 
SelfCheck
Question 1 Write the equation for the model, and then solve it algebraically.

Question 2 Write the equation for the model and then solve it algebraically. 
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Question 3 Find the value of n by balancing the equation algebraically. 
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