Download 2(x+3) - Cloudfront.net

Do Now – Math Minute
• Take 3 minutes to silently complete the math
minute.
• If you do not know how to do a problem,
please circle it and make sure to ask a
question!
Quick Write in Notebooks
1.) What does the word “distribute” mean to
you?
2.) What does the word “combine” mean to
you?
Evaluating Numerical Expressions
1.) Evaluate using
the order of operations: 2(3+4)
2.) Evaluate by multiplying
(distributing) the 2 first: 2(3+4)
What about Algebraic Expressions?
1.) What about if we had the expression 2(x+3).
How would you multiply (distribute) the 2 and
the (x + 3)?
2.) Let’s check our work by evaluating the
expressions for x = 1.
Notes – in your notebook
Distributive Property – When I multiply two or
more expressions, all terms of the first
expression are multiplied by all terms of the
second expression
Numerical:
Algebraic:
Geometric:
Mixed Practice
• Work in groups
• Criteria for good groupwork:
– Students come to consensus on answer
– Share your work with each other
– Ask “how” or “why” questions of each other if you
don’t understand
• It’s okay to make mistakes!!!
Equivalent Expressions
• What are expressions?
• What do you think “equivalent” means?
Is 3(2x + 4) an equivalent expression to 6(x+2)?
Explain to your partner why or why not. Show
your work!
Equivalent Expressions
Check if expressions are equivalent using at least
2 values for X.
3(2x + 4)
6(x+2)
Another example with negatives:
Check if equivalent Algebraically,
Numerically and Geometrically
-2(3x+6)
6(x-2)
But what about equations?
If -2(3x+6) is not equivalent to 6(x-2),
does that mean that I can’t solve: 2(3x+6) = 6(x-2)?
Conclusion:
If expressions are equivalent, they have an
infinite number of solutions.
If expressions are not equivalent, they have
either 0 or 1 solution.
Notes in notebook
Equivalent Expression: 2 expressions that
simplify to the same expression and when
equated, have infinite solution.
Example: Come up with an expression
equivalent to 3x + 18 and use substitution to
check your expression.
Practice
Combining in Math
Simplify the following expressions:
1.) 7 – 9
2.) -2x + 4x
3.) 2 + 2x + 5
What can I combine?
2 + 2x + 5
9x
Why can’t I combine numbers and
variables?
Example: 2 + 2x
In your notes
Combining Like Terms: I can combine terms
that have the same variable with the same
exponent.
I cannot combine unlike terms because…..
Practice – Combining Like Terms
Exit Slip
• Complete silently by yourself
• Show all your work
• Try your best! This is NOT for a grade, but will
help me see if I taught a good lesson and if
you understood today.