What is the relation between the numbers of amusement parks in 2004 and 2009?
Expression: A_(2009)=3344-148 Solution: 3196
Practice makes perfect
We know that in 2004 there were 3344 amusement parks and arcades, but in 2009 they decreased by 148. We want to find the number of amusement parks and arcades in 2009. To do so, we will start by representing this quantity by A_(2009). Then, we need to subtract the number of parks closed, 148, from the number in 2004, A_(2004).
A_(2009)=A_(2004)-148
Since we know that there were 3344 parks in 2004, we can substitute the given data into our expression and calculate A_(2009).
A_(2009)=3344-148=3196
A_(2009) is equal to 3196.
Extra
Writing Equations and Expressions
Remember that an algebraic expression consist of sums and/or products of numbers and variables. The variables are symbols used to represent numbers and values. Let's see some examples!
We represent a unknown quantity as x.
The distance is represented by d.
The velocity can be called v.
We can use these variables to write an expression. Usually the expressions are formed by a combination of variable terms and constant terms. The constant term can be any number. 3 x+ 5
Here, x represent the variable and 5 is the constant term. This is only one example, there is a lot of possibilities to form an algebraic expression.
Another important part of the algebraic expression is the operation. In the above example we used the symbol +, which means addition. We will summarize the operations in a table.
Now, a mathematical statement that contains algebraic expressions and an equals sign is called an equation.
2x+6 =24
Finding a value for the variable is called solving the equation, and the result is a solution. Some equations contain two variables and we can find the value for one variable in terms of the missing variable. For those of you who are interested in learning more about equations and expressions, you can read more about them on the following pages.
