Combining Like Terms
Dec 31, 2015
Vocabulary• When an operation separates an algebraic expression into
parts, each part is called a term.– Example: 2x + 5 2x and 5 are both terms
• Like terms contain the same variables and powers. – Example: 2x + 5 + x
• 2x & x are like terms because they both contain the variable x.• The power that the variables have in this problem is 1.
– Example: 2x² + 5 + x• 2x² and x do not have the same power, so they would not be like
terms.
• A term without a variable is called a constant. Constant terms are also like terms.– Example: 5 + 2x + 6
• 5 and 6 are constants, which means they are also like terms.
Algebra Tiles• Blue/Red Squares – represent variables squared
– Examples: x², y², -a², b², …..
• Green/Red Bars – represent variables– Examples: x, y, a, -b, …
• White/Red Units – represent constants– Examples: 5, 9, -8, 27, …
• The red side of all of these tiles represents negative and the blue, green, and white sides represent positive.
How to use Algebra Tiles
• Lay out the amount of algebra tiles to represent each term in the expression.
• Example:
4x + 8
Let’s try another example• Example 2:
6x + 5 + 2x
• Explain what you see with your tiles.
– 8 green bars, and 5 white units.
• Can you write that out as an expression?
– 8x + 5
Example 39x + 4 – 2x
9x + 4 + -2x
If I count up what I have. What do you think the green and red bars will do?
– Cancel each other out & make ZERO PAIRS!
– There are two zero pairs that you can make!
• Write your final answer out as an expression
*I don’t know how to show subtracting 2x.
*What you can do is change the problem to addition and make the number after the sign it’s opposite!
7x + 4