equations and expressions
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Sometimes an equation has a unknown number
13 - 7 = ? 3 x 4 = ? 10/2 = ?
instead of using a question mark
for the unknown amount,
we use a variable -- a symbol like N Y or x
5 + 25 = N 5 + 25 = Y 5 + 25 = x
the symbol that represents an unknown amount is called a Variable.
solve the equation to find x
5 + 25 = x
30 = x
the variable can be on either side of the equation & mixed in with the constant numbers.
2 + x = 5 n x 10 = 90 4 = 8 - y
constants are the known numbers.
variables are the unknown numbers.
the = sign separates the equation
into 2 equal sides.
An expression --
|
2 + X
N x 10 8 - Y |