Expressions & Formulas (Algebra 2)

Expressions and Formulas Expressions and Formulas

1) order of operations2) variable3) algebraic expression4) formula

Use the order of operations to evaluate expressions. Use Formulas.

Nurses setting up intravenous or IV fluids must control the flow rate F, in drops perminute.



They use the formula , where V is the volume of the solution in

milliliters, d is the drop factor in drops per milliliter, and t is the time in minutes.

t

dVF

x



They use the formula , where V is the volume of the solution in

milliliters, d is the drop factor in drops per milliliter, and t is the time in minutes.

t

dVF

x

Suppose a doctor orders 1500 milliliters of IV saline to be given over 12 hours.

Using the drop factor of 15 drops per milliliter, the expression

gives the correct flow rate for this patient’s IV.

60 x 12

15 x 1500


A numerical expression such as must have exactly one value. 60 x 12

15 x 1500



15 x 1500

In order to find that value, you must follow the _________________.



15 x 1500

In order to find that value, you must follow the _________________.order of operations



15 x 1500


Some students remember the order by using the following mnemonic:

PEMDAS

order of operations



15 x 1500



PEMDAS

lease

xcuse

y

ear

unt

ally

order of operations



15 x 1500



PEMDAS

lease

xcuse

y

ear

unt

ally

(parentheses / grouping symbols)

(exponents)

(multiplication – from left to right)

(division – from left to right)

(addition – from left to right)

(subtraction – from left to right)

order of operations


Find the value of 5]3)410(2[ 2


Find the value of 5]3)410(2[ 2 = [2(6)2 + 3] ÷ 5

= [2(36) + 3] ÷ 5

= [72 + 3] ÷ 5

= [75] ÷ 5

= 15


Find the value of

3

2

6

2 52 12 2


Find the value of

3

2

6

2 52 12 2


3

2

6

4 52 12

Find the value of

3

2

6

2 52 12 2


3

2

6

4 52 12

3

2

6

13 12

Find the value of

3

2

6

2 52 12 2


3

2

6

4 52 12

3

2

6

13 12

3

2 132

Find the value of

3

2

6

2 52 12 2


3

2

6

4 52 12

3

2

6

13 12

3

2 132

3

2 62

Find the value of

3

2

6

2 52 12 2


3

2

6

4 52 12

3

2

6

13 12

3

2 132

3

2 62

3

1 25

_________ are symbols, usually letters, used to represent unknown quantities.Variables



Expressions that contain at least one variable are called algebraic expressions.




You can evaluate an algebraic expression by replacing each variable with a numberand then applying the order of operations.





Evaluate the expression ( x – y )2 – 2wz, if w = 6, x = 0.4, y = , and z = – 3. 2

1






1

( x – y )2 – 2wz = ( 0.4 – 0.5 )2 – 2(6)( -3 )






1

( x – y )2 – 2wz = ( 0.4 – 0.5 )2 – 2(6)( -3 )

= ( – 0.1)2 – 12(– 3)






1

( x – y )2 – 2wz = ( 0.4 – 0.5 )2 – 2(6)( -3 )

= ( – 0.1)2 – 12(– 3)

= ( 0.01) + 36






1

( x – y )2 – 2wz = ( 0.4 – 0.5 )2 – 2(6)( -3 )

= ( – 0.1)2 – 12(– 3)

= ( 0.01) + 36

= 36.01


A _______ is a mathematical sentence that expresses the relationship between certain quantities.

formula



formula

If you know the value of every variable in the formula except one, you can find thevalue of the remaining variable.



formula


14 in

26 in

6 inThis shape is called a _________.



formula


14 in

26 in

6 inThis shape is called a _________.trapezoid



formula


14 in

26 in


The formula for calculating the area of a trapezoid is



formula


14 in

26 in


The formula for calculating the area of a trapezoid is 212

1bbhA


14 in

26 in

6 in

Find the area of the trapezoid:

212

1bbhA


14 in

26 in

6 in


212

1bbhA ininin 2614)6(

2

1


14 in

26 in

6 in


212


2

1

inin 40)6(2

1


14 in

26 in

6 in


212


2

1

inin 40)6(2

1

inin 40)3(


14 in

26 in

6 in


212


2

1

inin 40)6(2

1

inin 40)3(

2120in


14 in

26 in

6 in


212


2

1

inin 40)6(2

1

inin 40)3(

2120in

The area of the trapezoid is 120 square inches.


Expressions & Formulas (Algebra 2)

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