7th Grade Expressions, Equations and Inequalities

Translations

100

10 less than a number is 15

x - 10 = 15

200

^{1/2 of a number increased by 5 is 20}

1/2x + 5 = 20

300

Twice a number increased by 5 is 8

2x + 5 = 8

400

Three times a number minus 4 is 20

3x - 4 = 20

500

A number divided by 7 plus 9, the result is 49

(x/7) + 9 = 49

Word Problems

500

Sara wants to by some CD's that each cost $14, and a DVD costs $23. She has $65 to spend. Write and solve and equation to find how many CD's she can buy. 

let c = the number of CDs

14c + 23 = 65

One Step Equations

100

7x=49

x=7

200

x-14= -9

x=5

300

x/6=12

x=72

400

6.7+x=10

x=3.3

500

1/7x=5

x=35

Two Step Equations

100

x/3 + 5 = 10

x=15

200

-13 + 5x= 7

x=4

300

-7x- 11= 17

x=-4

400

4a +5.6= -2.8

a=-2.1

500

2/5x+12=2

x=-25

Vocab

100

7x + 10 = 25

What is the coefficient?

7

200

7x + 10 = 25

What is the variable?

x

300

7x + 10 = 25

What is the constant?

10

400

What is a variable?

A letter representing a number or unknown amount

500

What are the phrases we say to help us remember Coefficient AND Constant? 

"Coworker" and "Constantly Alone"