Example
There are 3 bags of marbles in the left-side pan of a
balance Each bag has the same number of marbles.
After you put 9 marbles in the right-side pan, the pans
hang evenly. How many marbles are in each bag?
(Assume the bags themselves have no weight.)
Draw a picture to represent the problem.
Write an expression for the number of marbles In
each pan.
number of marbles in left-side pan: 3x
number of marbies in right-side par: 9
Write an equation to show that the expressions
are equivalent 3x= 9.
What operation does the expression 3x involve?
Mellification
What is the inverse of this operation?
How do you isolate the variable in 3x = 97
Loude bollcombers, and Canal
#rop birt
When you isolate the variable, how do you keep the
equation balanced?