Year 8 Unit 3 Algebraic Expressions Review

Substitution

100

If x = 5 and y = 2, what is 3x - 2y?

11.

200

If x = 3 and y = 6, what is x² + 3y?

27.

300

If x = 4 and y = 5, what is 3y - 6x + 2y?

1

400

If x = 4 and y = -2, what is (3x² - y²) / 2?

22

500

If x = 4 and y=3, what is 3x² - 5y²?

3(4)² - 5(3)²

3(16) - 5(9)

48 - 45 = 3

Patterns

100

What is the rule for the following pattern?

5, 9, 13, 17, 21...

1 + 4n

200

What is the rule for the following pattern?

8, 3, -2, -7, -12...

13 - 5n

300

Find the 20th number for the following pattern:

3, 1, -1, -3, -5...

-35

400

Find the 37th number for the following pattern:

-35, -29, -23, -17, -11...

181

500

Find the 40th number for the following pattern:

113, 121, 129, 137, 145...

425

Combining Like Terms

100

Simplify:

3x - 2 + 5

3x + 3

200

Simplify:

5y + 14 - 3y - 5

2y + 9

300

3y + 7 - 2x + x + 6y - 5

9y - x + 2

400

5y² + 6x - 3y + 2x² + 3y - 5y² - 5x -2x²

x

500

Simplify:

5x² - 6x + x² - 3 + 7x - 4x² + 11

2x² + x + 8

Distributive Property

100

Simplify the expression:

5 + (x - 3)

2 + x OR x + 2

200

5y - 2(y + 7) - 4

3y - 18

300

3x - (2 - x) + 5

4x + 3

400

5y - 6(y + 3) - 7 - (2y + 4)

-3y - 29 

500

5x² - x(3x - 4) + 2x + 6(x² - 2x)

8x² - 6x

Creating Algebraic Expressions

100

Create an algebraic expression for the following phrase:

5 less than a number

x - 5

200

Create an algebraic expression for the following phrase:

The product of 6 and a number

6x

300

Create an algebraic expression for the following phrase:

The sum of three consecutive numbers.

x + (x+1) + (x+2)

3x + 3

400

Create an algebraic expression for the following phrase:

Triple the difference of half a number and 7.

3(x/2 - 7)

500

Create an algebraic expression for the following phrase

5 more than 3 times the difference of 6 and a number, divided by 2.

3(6 - x) + 5
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