Year 9 Algebra Review

Key Definitions

100

What is a pronumeral/variable?

Then give an example.

-> A letter used to represent a number. E.g. a, x, y.

200

What is a constant term and which one is it in the following expression?

6 + 3a -4b

-> A constant term is a number without a letter.

-> E.g. 6

300

What are like terms?

Give an example of a like term to "5a".

-> Terms that contain the exact same letter/s.

-> E.g.

400

What is the coefficient of "b" in the following expression?

2a-3b+4c

The coefficient of "b" is:

-> -3

500

Which two of the following are like terms?

3a, ab, -2a, 3a²

3a and -2a

Collecting Like Terms (+, -)

100

Simplify:

4x+2x+5x

=11x

200

Simplify:

8n-6n-3n

=-1n

300

Simplify:

5b+b+b-b

=6b

400

Simplify:

5xy + 2x - 3xy - x

2xy + x

500

Simplify:

3m^2-5m^2-3n-4n

=-2m^2-7n

Multiplying and Dividing Terms

100

Simplify:

2a\times4b

=8ab

200

Simplify:

2pxx5mxxp

=10mp^2

300

Simplify:

(8ab)/(2ac)

=(4b)/c

400

5m x (-3m)

-15m²

500

Simplify:

(12xxfxxf)\div(6xxfxxg)

=(2f)/g

Substitution

100

If a = 3, evaluate:

5+a+a

=11

200

If b = 4, evaluate

2b-b

=4

300

If m = 3 and k = 4, evaluate:

5m-mk

5xx(3)-(3)xx(4)=3

400

If r = 3, m = 2 and t = 5, evalute:

r + t - m

6

500

Write in expanded form, then substitute x = 3 and y = 2.

3x^2y

2timesxtimesxtimesy = 2times3times3times2

=36

Expand Brackets

100

Expand:

4(x+2)

4x+8

200

Expand:

3(n-2m)

3n-6mn

300

Expand:

-2(m + 2)

-2m - 4

400

Expand:

-8x(2x+y)

-16x^2-8xy

500

Expand:

-5b(3-b^2)

-15b+5b^3