Math 8 · Unit 2: Expressions, formulae and equations · Cambridge Lower Secondary Maths Stage 8

Questions

1. 1. Solve 3x + 5 = 20.

   • x = 5
   • x = 8.3
   • x = 15
   • x = 25/3
   Check

2. 2. Solve 5x − 2 = 2x + 7.

   • x = 1
   • x = 9
   • x = 3
   • x = 5/7
   Check

3. 3. Solve 2(x + 4) = 18.

   • x = 11
   • x = 9
   • x = 5
   • x = 7
   Check

4. 4. Solve x/4 = 7.

   • x = 3
   • x = 1.75
   • x = 11
   • x = 28
   Check

5. 5. Solve 7 − x = 2.

   • x = −5
   • x = 3.5
   • x = 9
   • x = 5
   Check

6. 6. Solve 4x + 3 = x + 18.

   • x = 5
   • x = 3
   • x = 4.2
   • x = 7
   Check

7. 7. Three consecutive numbers add to 48. What is the smallest?

   • 12
   • 14
   • 16
   • 15
   Check

8. 8. Solve (x + 1)/3 = 4.

   • x = 3
   • x = 11
   • x = 13
   • x = 1/3
   Check

9. 9. Solve 6 − 2x = 14.

   • x = 10
   • x = −10
   • x = 4
   • x = −4
   Check

10. 10. I think of a number, double it and add 9 to get 25. What is it?

    • 12.5
    • 8
    • 7
    • 17
    Check

11. 11. Solve 3(2x − 1) = 2(x + 5).

    • x = 4
    • x = 3
    • x = 13/4
    • x = 2
    Check

12. 12. A rectangle has length 2x and width x. Perimeter 36. Find x.

    • 9
    • 12
    • 18
    • 6
    Check

13. 13. Solve 0.5x = 9.

    • x = 8.5
    • x = 9.5
    • x = 18
    • x = 4.5
    Check

14. 14. Solve 9x = 4x.

    • x = 0
    • no solution
    • x = 5
    • x = 9/4
    Check

15. 15. Angles in a triangle are x, 2x, 3x. Find x.

    • 36°
    • 30°
    • 20°
    • 60°
    Check