WRITING EQUATIONS WITH VARIABLES! MS. DIEHL / OCTOBER 6, 2011.

WRIT

ING

EQUATIO

NS WIT

H

VARIA

BLES!

MS .

DI E

HL /

OCTO

BER 6,

2011

DO NOWHW OUT ON YOUR DESK!

5.5(x) + 2(y) when x = 3 and y =

2.15(g) – 2 when g = 5

12r x 8b when r= and b=3

2

1

4

1

HW

CHECK!

ACTIVITY

On your DO NOW sheet draw a chart that looks like the following:

# Expression

Letter/Answer Match

I can translate words into math sentences!

REVIEW:

Variable:

A symbol for a number that we do not know yet.

Example: X, Y

A changing quantity

What is a variable in your life?

Substitution:

Replacing variables with numbers

10X + 4Y + 6Coefficient

Constant

Variable

TODAY

We are going to write our own equations

Our equations we write will have VARIABLES and CONSTANTS and COEFFICIENTS!

KEY WORDS

What key words tell us to add, subtract, multiply or divide?

Operation Keywords

Addition

Subtraction

Division

Multiplication

Variable

LETS WRITE AN EXPRESSION:

John makes $6 just for showing up to work every morning. He makes $8 every hour he works.

“every hour” = X (my variable) because I DON’T know for sure what it is

6 = my constant because I DO know what it is.

8 = my coefficient

8X + 6

One more time…What is my variable?What is my constant?

What is my variable?What are my constant(s)?What is my answer?

(3)X+ 14 = 300

SOMETIMES…

We have more than ONE constant

The difference between the number of hotdogs I buy and the number of candy bars I buy is 5.

What is my constant(s)?What is my variable?

X - y = 5

The quotient of x and 3 equals v

What is my constant?What are my variables?

WHITEBOARDS

Some number minus 7 equals 24.

The length of a football field is 30 yards more than its width. 

The sum of 8 and f multiplied by the difference of m and 12.

REMEMBER!

What we learn each day builds on what we learned yesterday, last week, and at the beginning of the year!

It is important to stay focused, stay motivated, and work hard so we can all reach our goals of being proficient or advanced on TCAP!

I can translate words into math sentences!

EXIT TICKET!WRITE THE EXPRESSION OR EQUATION. DO NOT SOLVE!

The product of a number plus 7 equals 7.

The number of gallons of gas I buy times the price of $3.28 equals the amount of money I spend a week.

The sum of a number plus 2 equals 17

Three hundred and five squared minus the sum of y and 19.

CHALLENGE: nine less than the total of a number and two