Parts of an Expression
What is an example of a variable?
Any letter we use to show an unknown value
(x, w, z, m, etc)
Simplify: 3x + 2x
5x
What operation am I doing in this expression?
5t
I'm doing 5*t, so I'm MULTIPLYING (since I don't see another operation)
When I have a positive and a negative version of the same number, we call them 2 things. Give me one of them (or both for double points!)
Zero Pairs
Opposite Numbers
What is our order of operations?
Parentheses
Exponents
Multiply/Divide (from left to right and top to bottom)
Add/Subtract (from left to right)
What is the difference between an expression and an equation?
An expression has an equal sign, an equation does not
What are our terms in the expression:
5y + 3 - 2y
+5y, +3, -2y
(Simplified expression would be 3y + 3)
Evaluate the expression 4(5)
20
If I don't see an operation, I'm multiplying!
What direction on the number line do I move if I ADD a NEGATIVE?
Left or Down
10+3(2)
16
In the expression 3x + 2, what is the coefficient?
3
Simplify:
2x + 3y + 2
2x + 3y + 2
We can't combine x and y terms!
Evaluate the expression 2x + 3
if x = 10
NO CALCULATOR:
(3) + (-6)
-3
2 + 4(8-5)
14
What is the constant in the expression 4 + 2y?
4 (it's always the number BY ITSELF, not next to the variable!)
Simplify:
3(2w - 4)
6w - 12
What order am I going to do operations in for this expression if I was evaluating it?
(9 + x)/10
(9+x) first - parentheses
/10 second - dividing
NO CALCULATOR:
(4) - (-10)
14 (Keep, Change, Flip!)
18 - 3(2+4)
0
What is the value of x in the expression 2x + 3?
Trick question! We don't know, and we don't care, because it's an expression, not an equation.
We CANNOT ASSUME IT'S 1!
How many terms will this expression have when fully simplified? (You do not have to simplify it, but it might help!)
3w + 4x2 - w + 6 - 2w + x2
There will be 2 terms left!
3w - w - 2w is 0
4x2+x2 is 5x2
There's nothing to combine with 6, so our simplified expression is:
5x2 + 6
Evaluate the expression 3(a - 12)
if a = -2
3(-2 - 12)
3(-14)
-42
You can also distribute first!
NO CALCULATOR, show your work!
2(3 - 5)
-4
(3-5) -> -2
-2 * 2 = -4
2(3 - 6)/3 (I'll rewrite this on the board so it looks better)
-2