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Linear Equations

Secondary 1 practice

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Linear Equations practice questions

Secondary 1 topics, the foundation the O-Level Mathematics 4052 syllabus builds on. Every question below has a full worked solution.

When a student gets a question wrong in Math Amigo, it does not show the answer straight away. It reads the working, identifies the step that went wrong, and asks a question that points at the correction. The worked solution is there once a genuine attempt has been made.

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Read the Linear Equations study notes: the method, worked examples and the mistakes that cost marks. Free, no account.

What this topic covers

Worked examples

Example 1

Solve 5(a−5)=−455(a - 5) = -45.
Show the worked solution
  • 5(a−5)=−455(a - 5) = -45
  • 5a−25=−45expand5a - 25 = -45 \quad \scriptsize\textit{expand}
  • 5a=−45+25add 25 to both sides5a = -45 + 25 \quad \scriptsize\textit{add 25 to both sides}
  • 5a=−205a = -20
  • a=−205a = -\frac{20}{5}
  • a=−4a = -4

Answer: −4-4

Example 2

Solve 4x+13=3x−25\frac{4x + 1}{3} = \frac{3x - 2}{5}.
Show the worked solution
  • 4x+13=3x−25\frac{4x + 1}{3} = \frac{3x - 2}{5}
  • 5(4x+1)=3(3x−2)cross multiply5(4x + 1) = 3(3x - 2) \quad \scriptsize\textit{cross multiply}
  • 20x+5=9x−620x + 5 = 9x - 6
  • 11x=−1111x = -11
  • x=−1x = -1

Answer: −1-1

Example 3

Jun Wei has 1010 more 10-cent coins than 20-cent coins. The total value of all the coins is $6.10\$6.10. Find the number of 20-cent coins.
Show the worked solution
  • Let xx be the number of 20-cent coins. define variable\scriptsize\textit{define variable}
  • Number of 10-cent coins =x+10= x + 10.
  • Total value in cents: 20x+10(x+10)=61020x + 10(x + 10) = 610
  • 20x+10x+100=61020x + 10x + 100 = 610
  • 30x+100=61030x + 100 = 610
  • 30x=51030x = 510
  • x=17x = 17
  • The number of 20-cent coins is 1717.

Answer: 1717

Questions parents ask

Is it really free?

The free plan is permanent and does not ask for a card. It has daily limits on the AI feedback, and the paid plans lift them.

Which syllabus does this follow?

O-Level Mathematics (4052), for Singapore secondary students. Math Amigo covers Secondary 1 to 4, both O-Level Mathematics and Additional Mathematics.

Will it just show my child the answer?

No. On a wrong answer it looks at the working, points to the step that went wrong, and asks a question that helps the student find the correction. The full worked solution is available after a genuine attempt.

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