Download 1-1 Expressions and Formulas

1-1 Expressions and
Formulas
To use order of operations
Replacing variable with number in
expression and Formulas
What is a Expression?
It is a mathematical statement with
variables. 3x + 4
 So what is an Equation?
It an expression that equals a given value,
thus you can solve an equation.

An Expression you can fill in the variables
with numbers and evaluate.
Using the Order of Operations
What is the order of Operation?
The way a expression is evaluated
Parentheses
Exponents
Multiplication or Division
(from Left to Right)
Addition or Subtraction
(From Left to Right)
How to Remember the order.
One way is with a Sentence
Parentheses
Exponents
Multiplication or Division
(from Left to Right)
Addition or Subtraction
(From Left to Right)

Please Excuse My Dear Aunt Sally
Is it really important to use Left to
Right
Is the answer 25 or 1 ?
40  8  5
Find the value of this expression
using the order of operation
384  37  2  3
3
First Step
(7-2)=5
384  35  3
3
384  3125  3
384  375 3
9 3
So the expression is evaluate to 3
You can also plug numbers in for
variable and then use the order of
operation to evaluate

Evaluate

x y x  y
if x = 2 and y = 3.4
2

The expression becomes easy to
work with as each step is used.
2  3.4(2  3.4)
2
2  3.4(4  3.4)
2  3.4(0.6)
2  2.04
 0.04
Lets Evaluate a Formula
The volume of this classroom has the
Formula V = lwh;
where l is length, w is wide and h is height
Lets guess at the measurements
L is 18 feet; w is 12 feet and h is 10 feet
Thus V = (18)(12)(10)

So the volume equals
2160 feet cubed
Is this the correct answer?
We did the math right.
So if the answer is wrong what is the problem?
Could the equation by wrong?
Homework
Page 9 – 10
#17 – 33 odd, #37- 47 odd and #54