Understanding Algebra!

T-Tables and Algebraic Expressions
Algebra is used to study relationships between numbers. We can see that in a t-table

The relationship between the two numbers is we multiply by 3 and add 1.

Algebraic Expressions
We can also use algebra to determine change. For instance if you were babysiting
and you were paid $8 an hour, you could use algebra to determine how much money you
were going to make. On Tuesdays you babysit for 4 hours and on Saturday you babysit for 6 hours.
Every time you babysit the number of hours changes (hours is the variable)
We can use the algebraic expression (a combination of letters, numbers and operations to help us determine how much we will make.

8H - is the algebraic expression. (8 represents the amount we make each hour, and H represents the number of hours you babysit)

Now we can also figure out how many hours we need to babysit to make a certain amount of money.

8H = 40 (8 represents the amount we make each hour. H represents the number of hours we work, and 40 is the total amount we need to make for that new pair of shoes)

8H = 40  First we need to isolate H (In order for H to reveal himself he needs to be by himself.)
8H = 40  We can get rid of the 8 by doing the opposite operation. Whatever we do on one side
 8       8    we need to do on the other side.
                 Now we have to do the division
H = 5       That represents the number of hours we need to work to make $40

Now you Try It!

1. To rent a movie it costs $2.50 each day. If I rented the movie for 4 days how much money did it cost me. What is the algebraic expression.
I rented a movie and when I returned my bill was $10.00 how many hours did I rent the movie for?

2. Michael is making chocolate chip oatmeal cookies and it calls for twice as much chocolate chips as it does oatmeal. If there is 150 mL in total what is the amount of chocolate chips that you need.