Proportion equations

The Maths Habit

Which is the odd one out?

y = 4xy = x + 4y = 4xy = x4

y = x + 4: the only one that adds

y = 4 ÷ x: y falls as x grows

Direct proportion: y = kx. The answer to y ÷ x stays the same.
Inverse proportion: y = kx. The answer to x × y stays the same.

Direct, inverse or neither?

y = 7x Direct

Direct, inverse or neither?

y = x3 Direct

y = 20x

x	1	2	4	5
y

y = 4x. Direct, inverse or neither?

x	1	2	4	5
y	4	8	16	20
y ÷ x	4	4	4	4
x × y	4	16	64	100

AnswerDirect

y = 30x. Direct, inverse or neither?

x	1	2	5	10
y	30	15	6	3
y ÷ x	30	7.5	1.2	0.3
x × y	30	30	30	30

AnswerInverse

y = 4x. Direct, inverse or neither?

x	1	2	4	5
y	4	8	16	20
y ÷ x	4	4	4	4
x × y	4	16	64	100

AnswerDirect

y = 2x − 3. Direct, inverse or neither?

x	2	3	4	5
y	1	3	5	7
y ÷ x	0.5	1	1.25	1.4
x × y	2	9	20	35

AnswerNeither

y = 4x. Direct, inverse or neither?

x	1	2	4	5
y	4	8	16	20
y ÷ x	4	4	4	4
x × y	4	16	64	100

AnswerDirect

y = 36x. Direct, inverse or neither?

x	2	3	4	6
y	18	12	9	6
y ÷ x	9	4	2.25	1
x × y	36	36	36	36

AnswerInverse

y = 4x. Direct, inverse or neither?

x	1	2	4	5
y	4	8	16	20
y ÷ x	4	4	4	4
x × y	4	16	64	100

AnswerDirect

y = x2. Direct, inverse or neither?

x	2	4	6	8
y	1	2	3	4
y ÷ x	0.5	0.5	0.5	0.5
x × y	2	8	18	32

AnswerDirect

y = 4x. Direct, inverse or neither?

x	1	2	4	5
y	4	8	16	20
y ÷ x	4	4	4	4
x × y	4	16	64	100

AnswerDirect

y = x². Direct, inverse or neither?

x	1	2	3	4
y	1	4	9	16
y ÷ x	1	2	3	4
x × y	1	8	27	64

AnswerNeither

Proportion equations worksheet, page 1

Answer sheet

When x is 2, 4 and 10, y is 6, 12 and 30. Write the equation.
y = 3x
When x is 2, 4 and 8, y is 12, 6 and 3. Write the equation.
y = 24x

Is y = x4 direct, inverse or neither?
Direct
Is xy = 18 direct, inverse or neither?
Inverse
Is y = 3x + 2 direct, inverse or neither?
Neither
When x is 2, 4 and 5, y is 10, 5 and 4. Write the equation.
y = 20x

Exit tickets to print