Year 9 Mathematics Unit 2 · Checkpoint 4 Block D: Lessons 16–20 ~30 min

Checkpoint 4: Linear Relationships

This checkpoint assesses your understanding of mixed algebra review, equations review, patterns and generalisation, problem solving and the capstone challenge. It covers Lessons 16–20.

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01

Select the best answer

Foundation

1. Simplify $5x + 3y - 2x + y$.

A
$3x + 3y$
B
$3x + 4y$
C
$7x + 4y$
D
$3x + 2y$
Foundation

2. Expand $3(x - 4)$.

A
$3x - 4$
B
$x - 12$
C
$3x - 12$
D
$3x + 12$
Standard

3. Solve $4x - 7 = 17$.

A
$x = 6$
B
$x = 5$
C
$x = 10$
D
$x = 24$
Standard

4. The next term in the sequence 3, 7, 11, 15, ... is:

A
16
B
18
C
19
D
20
Standard

5. Solve $\dfrac{x + 3}{2} = 5$.

A
$x = 7$
B
$x = 8$
C
$x = 10$
D
$x = 13$
Standard

6. Solve $-3x + 5 < 14$.

A
$x < -3$
B
$x > -3$
C
$x < 3$
D
$x > 3$
Standard

7. A plumber charges \$50 call-out plus \$40 per hour. For a \$170 bill, the hours worked are:

A
2
B
3
C
4
D
5
Advanced

8. Expand and simplify $(x + 2)(x - 3)$.

A
$x^2 - 6$
B
$x^2 + x - 6$
C
$x^2 - x - 6$
D
$x^2 - 5x - 6$
Advanced

9. The rule for the nth term of 5, 9, 13, 17, ... is:

A
$T_n = 4n + 1$
B
$T_n = 4n + 5$
C
$T_n = 5n - 1$
D
$T_n = 3n + 2$
Advanced

10. Make $x$ the subject of $y = \dfrac{x + 2}{3}$.

A
$x = 3y + 2$
B
$x = 3y - 2$
C
$x = \dfrac{y}{3} - 2$
D
$x = \dfrac{y - 2}{3}$
02

Show all working

Standard

11. Simplify the following.

(a) $3a + 5b - a + 2b$ (1 mark)
(b) $2(x + 3) + 3(x - 1)$ (2 marks)3 MARKS

Standard

12. Solve the following equations.

(a) $5x - 3 = 22$ (1 mark)
(b) $\dfrac{2x + 1}{3} = 5$ (2 marks)
(c) $4 - 2x \geq 10$ (2 marks)5 MARKS

Standard

13. Patterns and formulas.

(a) Find the 20th term of the sequence with rule $T_n = 3n + 7$. (1 mark)
(b) Make $h$ the subject of $A = \dfrac{1}{2}bh$. (2 marks)3 MARKS

Advanced

14. Word problems.

(a) The sum of three consecutive even numbers is 84. Find the numbers. (3 marks)
(b) A car rental costs \$45 per day plus \$0.25 per km. For a total cost of \$95 and 120 km driven, how many days was the car rented? (2 marks)5 MARKS

✅ Comprehensive Answers

❓ Multiple Choice

1. B — $5x - 2x + 3y + y = 3x + 4y.

2. C — $3 \times x + 3 \times (-4) = 3x - 12.

3. A — $4x = 24 \Rightarrow x = 6.

4. C — Common difference = 4. $15 + 4 = 19.

5. A — $x + 3 = 10 \Rightarrow x = 7.

6. B — $-3x < 9 \Rightarrow x > -3 (flip sign).

7. B — $50 + 40h = 170 \Rightarrow 40h = 120 \Rightarrow h = 3.

8. C — $x^2 - 3x + 2x - 6 = x^2 - x - 6.

9. A — Common difference = 4, first term = 5. $T_n = 4n + 1.

10. B — $3y = x + 2 \Rightarrow x = 3y - 2.

✍ Short Answer Model Answers

Q11 (3 marks): (a) $3a - a + 5b + 2b = 2a + 7b$ [1]. (b) $2x + 6 + 3x - 3 = 5x + 3$ [2].

Q12 (5 marks): (a) $5x = 25 \Rightarrow x = 5$ [1]. (b) $2x + 1 = 15 \Rightarrow 2x = 14 \Rightarrow x = 7$ [2]. (c) $-2x \geq 6 \Rightarrow x \leq -3$ (flip sign) [2].

Q13 (3 marks): (a) $T_{20} = 3(20) + 7 = 60 + 7 = 67$ [1]. (b) $2A = bh \Rightarrow h = \dfrac{2A}{b}$ [2].

Q14 (5 marks): (a) Let $n$ = first even number: $n + (n+2) + (n+4) = 84 \Rightarrow 3n + 6 = 84 \Rightarrow 3n = 78 \Rightarrow n = 26$. Numbers: 26, 28, 30 [3]. (b) $45d + 0.25(120) = 95 \Rightarrow 45d + 30 = 95 \Rightarrow 45d = 65 \Rightarrow d = 1.44$ days (or 1 day 11 hours) [2].

Mark checkpoint as complete

Tick when you have finished all questions and checked your answers.