1. Solve x + 9 = 16.
- A7
- B25
- C9
- D16
Show answer
Answer: A) 7
Subtract 9 from both sides: x = 16 − 9 = 7.
Class 7 Simple Equations — practice questions with answers
Simple Equations · 5 sample questions from the school syllabus. Try each one, then open the answer and the worked solution.
2. Write the equation for: 'Add 8 to a number x and the result is 20.'
- Ax + 8 = 20
- B8x = 20
- Cx − 8 = 20
- D20 + 8 = x
Show answer
Answer: A) x + 8 = 20
Adding 8 to x gives x + 8, and this equals 20, so the equation is x + 8 = 20.
3. In a class, the number of girls is 5 more than the number of boys. If there are 18 boys, write and solve an equation for the number of girls.
- A46
- B25
- C23
- D21
Show answer
Answer: C) 23
Let girls = g. g = boys + 5 = 18 + 5 = 23. (Equation: g − 5 = 18 → g = 23.)
4. Solve 3(x + 4) = 2(x + 9).
- A-6
- B6
- C14
- D30
Show answer
Answer: B) 6
Expand both sides: 3x + 12 = 2x + 18. Gather: 3x − 2x = 18 − 12 → x = 6. Check: 3(6 + 4) = 30 and 2(6 + 9) = 30 ✓. Answer −6 subtracts the constants the wrong way round; 14 comes from multiplying only the first term inside the left bracket (3x + 4 = 2x + 18); 30 is the value each side takes, not the value of x.
5. The sum of two consecutive multiples of 7 is 105. What is the larger multiple?
- A49
- B52.5
- C63
- D56
Show answer
Answer: D) 56
Consecutive multiples of 7 differ by 7, so take them as 7n and 7n + 7. Then 14n + 7 = 105 → 14n = 98 → n = 7, and the multiples are 49 and 56, with 49 + 56 = 105 ✓. The larger is 56; 49 is the smaller one. Answer 52.5 halves 105 as though the two numbers were equal, and 63 is one multiple too far.
Practise all 90 questions free →
10 free questions a day without an account — unlimited with a free account.